# Patent

## Title
Swap operations in memory

## Abstract

Examples of the present disclosure provide apparatuses and methods related to performing swap operations in a memory. An example apparatus might include a first group of memory cells coupled to a first sense line and configured to store a first element. An example apparatus might also include a second group of memory cells coupled to a second sense line and configured to store a second element. An example apparatus might also include a controller configured to cause the first element to be stored in the second group of memory cells and the second element to be stored in the first group of memory cells by controlling sensing circuitry to perform a number operations without transferring data via an input/output (I/O) line.

## Background
PRIORITY INFORMATION
This application is a Non-Provisional of U.S. Provisional Application No. 62/045,193, filed Sep. 3, 2014, the contents of which are incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates generally to semiconductor memory apparatuses and methods, and more particularly, to apparatuses and methods related to performing swap operations in a memory.
BACKGROUND
Memory devices are typically provided as internal, semiconductor, integrated circuits in computers or other electronic systems. There are many different types of memory including volatile and non-volatile memory. Volatile memory can require power to maintain its data (e.g., host data, error data, etc.) and can include random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), synchronous dynamic random access memory (SDRAM), and thyristor random access memory (TRAM), among others. Non-volatile memory can provide persistent data by retaining stored data when not powered and can include NAND flash memory, NOR flash memory, and resistance variable memory such as phase change random access memory (PCRAM), resistive random access memory (RRAM), and magnetoresistive random access memory (MRAM), such as spin torque transfer random access memory (STT RAM), among others.
Electronic systems often include a number of processing resources (e.g., one or more processors), which may retrieve and execute instructions and store the results of the executed instructions to a suitable location. A processor can comprise a number of functional units (e.g., herein referred to as functional unit circuitry (FUC)) such as arithmetic logic unit (ALU) circuitry, floating point unit (FPU) circuitry, and/or a combinatorial logic block, for example, which can execute instructions to perform logical operations such as AND, OR, NOT, NAND, NOR, and XOR logical operations on data (e.g., one or more operands).
A number of components in an electronic system may be involved in providing instructions to the functional unit circuitry for execution. The instructions may be generated, for instance, by a processing resource such as a controller and/or host processor. Data (e.g., the operands on which the instructions will be executed to perform the logical operations) may be stored in a memory array that is accessible by the FUC. The instructions and/or data may be retrieved from the memory array and sequenced and/or buffered before the FUC begins to execute instructions on the data. Furthermore, as different types of operations may be executed in one or multiple clock cycles through the FUC, intermediate results of the operations and/or data may also be sequenced and/or buffered.
In many instances, the processing resources (e.g., processor and/or associated FUC) may be external to the memory array, and data can be accessed (e.g., via a bus between the processing resources and the memory array) to execute instructions. Data can be moved from the memory array to registers external to the memory array via a bus.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an apparatus in the form of a computing system including a memory device in accordance with a number of embodiments of the present disclosure.
FIG. 2A illustrates a schematic diagram of a portion of a memory array in accordance with a number of embodiments of the present disclosure.
FIG. 2B illustrates a schematic diagram of a portion of a memory array in accordance with a number of embodiments of the present disclosure.
FIG. 3 illustrates a schematic diagram of a portion of a memory array in accordance with a number of embodiments of the present disclosure.
FIGS. 4A-4Q illustrate the states of memory cells of a portion of an array at a number of particular phases associated with performing a swap operation in accordance with a number of embodiments of the present disclosure.
FIG. 5 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure.
FIG. 6 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure.
FIG. 7 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure.
FIG. 8 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure.
FIG. 9 illustrate a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure.
FIG. 10 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure.
FIG. 11 is a schematic diagram illustrating sensing circuitry having selectable logical operation selection logic in accordance with a number of embodiments of the present disclosure.
FIG. 12 is a logic table illustrating selectable logic operation results implemented by a sensing circuitry in accordance with a number of embodiments of the present disclosure.



DETAILED DESCRIPTION
The present disclosure can include apparatuses and methods related to performing swap operations in a memory. A swap operation can be performed on a first element (e.g., first vector) and a second element (e.g., second vector). An element can be stored in a group memory cells coupled to a sense line. For example, a first group of memory cells coupled to a first sense line can be configured to store a first element. A second group of memory cells coupled to a second sense line can be configured to store a second element. The swap operation can store the first element in the second group of memory cells and the second element in the first group of memory cells by performing a number of operations without transferring data via an input/output (I/O) line.
As used herein, a first element and a second element can be numerical values that can be stored (e.g., as bit-vectors) in an array. As used herein, swapping may refer to storing a first element, which is originally (e.g., initially) stored in a first group of memory cells, in a second group of memory cells in which a second element is originally stored, and storing the second element, which is originally stored in the second group of memory cells, in the first group of memory cells.
In a number of examples, an element can represent an object and/or other construct, which may be represented by a bit-vector. As an example, a swap operation can be performed to swap bit-vectors that represent respective objects.
A number of embodiments of the present disclosure can provide a reduction of the number of operations (e.g., computations, functions, etc.) and/or time involved in performing a number of swap operations (e.g., swap functions) relative to previous approaches. For instance, the number of computations and/or the time can be reduced due to an ability to perform various swap operations in parallel (e.g., simultaneously). Performing a number of swap operations as described herein can also reduce power consumption as compared to previous approaches. In accordance with a number of embodiments, a swap operation can be performed on elements (e.g., data in the form of bit-vectors stored in an array) without transferring data out of the memory array and/or sensing circuitry via a bus (e.g., data bus, address bus, control bus, etc.), which can reduce the time and/or power needed to transfer data to a host in order to perform the swap operation. The result of the swap operation can be provided to other single instruction multiple data (SIMD) operations (e.g., bit-vector division) and/or advanced pattern search applications, for example. A swap operation can involve performing a number of logical operations (e.g., AND operations, OR operations, SHIFT operations, and INVERT operations, etc.). However, embodiments are not limited to these examples. As used herein SIMD operations can be defined as performing a same operation on multiple elements in parallel (e.g., simultaneously).
In various previous approaches, elements (e.g., data stored in a particular group of memory cells and data stored in a different particular group of memory cells) to be swapped may be transferred from the array and sensing circuitry to a number of registers via a bus comprising input/output (I/O) lines. The number of registers can be used by a processing resource such as a processor, microprocessor, and/or compute engine, which may comprise ALU circuitry and/or other functional unit circuitry configured to perform the appropriate logical operations to swap the elements and to store the result. However, often only a single swap operation can be performed by the ALU circuitry at a given time, and transferring data to/from memory from/to registers via a bus can involve significant power consumption and time requirements. Even if the processing resource is located on a same chip as the memory array, significant power can be consumed in moving data out of the array to the compute circuitry (e.g., ALU), which can involve performing a sense line address access (e.g., firing of a column decode signal) in order to transfer data from sense lines onto I/O lines, moving the data to the array periphery, and providing the data to a register in association with performing a swap operation, for instance.
In the following detailed description of the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration how one or more embodiments of the disclosure may be practiced. These embodiments are described in sufficient detail to enable those of ordinary skill in the art to practice the embodiments of this disclosure, and it is to be understood that other embodiments may be utilized and that process, electrical, and/or structural changes may be made without departing from the scope of the present disclosure. As used herein, the designators “M,” “N,” “J,” “R,” “S,” “U,” “V,” “X,” “Y,” and “W,” particularly with respect to reference numerals in the drawings, indicates that a number of the particular feature so designated can be included. As used herein, “a number of” a particular thing can refer to one or more of such things (e.g., a number of memory arrays can refer to one or more memory arrays).
The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example, 130 may reference element “30” in FIG. 1, and a similar element may be referenced as 230 in FIG. 2. As will be appreciated, elements shown in the various embodiments herein can be added, exchanged, and/or eliminated so as to provide a number of additional embodiments of the present disclosure. In addition, as will be appreciated, the proportion and the relative scale of the elements provided in the figures are intended to illustrate certain embodiments of the present invention, and should not be taken in a limiting sense.
FIG. 1 is a block diagram of an apparatus in the form of a computing system 100 including a memory device 160 in accordance with a number of embodiments of the present disclosure. As used herein, a memory device 160, a memory array 130, and/or sensing circuitry 150 might also be separately considered an “apparatus.”
System 100 can include a host 110 coupled to memory device 160, which can include a memory array 130. Host 110 can be a host system such as a personal laptop computer, a desktop computer, a digital camera, a mobile telephone, or a memory card reader, among various other types of hosts. Host 110 can include a system motherboard and/or backplane and can include a number of processing resources (e.g., one or more processors, microprocessors, or some other type of controlling circuitry). The system 100 can include separate integrated circuits or both the host 110 and the memory device 160 can be on the same integrated circuit. The system 100 can be, for instance, a server system and/or a high performance computing (HPC) system and/or a portion thereof. Although the example shown in FIG. 1 illustrates a system having a Von Neumann architecture, embodiments of the present disclosure can be implemented in non-Von Neumann architectures (e.g., a Turing machine), which may not include one or more components (e.g., CPU, ALU, etc.) often associated with a Von Neumann architecture.
For clarity, the system 100 has been simplified to focus on features with particular relevance to the present disclosure. The memory array 130 can be a DRAM array, SRAM array, STT RAM array, PCRAM array, TRAM array, RRAM array, NAND flash array, and/or NOR flash array, for instance. The array 130 can comprise memory cells arranged in rows coupled by access lines (which may be referred to herein as word lines or select lines) and columns coupled by sense lines (which may be referred to herein as digit lines or data lines). Although a single array 130 is shown in FIG. 1, embodiments are not so limited. For instance, memory device 160 may include a number of arrays 130 (e.g., a number of banks of DRAM cells). An example DRAM array is described in association with FIG. 2.
The memory device 160 includes address circuitry 142 to latch address signals provided over an I/O bus 156 (e.g., a data bus) through I/O circuitry 144. Address signals are received and decoded by a row decoder 146 and a column decoder 152 to access the memory array 130. Data can be read from memory array 130 by sensing voltage and/or current changes on the sense lines using sensing circuitry 150. The sensing circuitry 150 can read and latch a page (e.g., row) of data from the memory array 130. The I/O circuitry 144 can be used for bi-directional data communication with host 110 over the I/O bus 156. The write circuitry 148 is used to write data to the memory array 130.
Controller 140 decodes signals provided by control bus 154 from the host 110. These signals can include chip enable signals, write enable signals, and address latch signals that are used to control operations performed on the memory array 130, including data read, data write, and data erase operations. In various embodiments, the controller 140 is responsible for executing instructions from the host 110. The controller 140 can be a state machine, a sequencer, or some other type of control circuitry.
An example of the sensing circuitry 150 is described further below in association with FIG. 2. For instance, in a number of embodiments, the sensing circuitry 150 can comprise a number of sense amplifiers and a number of compute components, which may comprise an accumulator and can be used to perform logical operations (e.g., on data associated with complementary sense lines) in association with performing swap operations in accordance with embodiments described herein. In a number of embodiments, the sensing circuitry (e.g., 150) can be used to perform swap operations on data stored in array 130 and to store the results of the swap operations back to the array 130 without transferring data via a sense line address access (e.g., without firing a column decode signal). As such, a swap operation can be performed using sensing circuitry 150 rather than and/or in addition to being performed by processing resources external to the sensing circuitry 150 (e.g., by a processor associated with host 110 and/or other processing circuitry, such as ALU circuitry, located on device 160 (e.g., on controller 140 or elsewhere)).
In various previous approaches, data associated with a swap operation, for instance, would be read from memory via sensing circuitry and provided to an external ALU. The external ALU circuitry would perform the swap operations and the result could be transferred back to the array via the local I/O lines. In contrast, in a number of embodiments of the present disclosure, sensing circuitry (e.g., 150) is configured to perform a swap operation on data stored in memory cells in memory array 130 and store the result back to the array 130 without enabling a local I/O line coupled to the sensing circuitry.
As such, in a number of embodiments, registers and/or an ALU external to array 130 and sensing circuitry 150 may not be needed to perform the swap operation as the sensing circuitry 150 can perform the appropriate computations involved in performing the swap operation using the address space of memory array 130. Additionally, the swap operation can be performed without the use of an external processing resource.
FIG. 2A illustrates a schematic diagram of a portion of a memory array 230 including sensing circuitry 250 in accordance with a number of embodiments of the present disclosure. In FIG. 2A, a memory cell comprises a storage element (e.g., capacitor) and an access device (e.g., transistor). For instance, a first memory cell comprises transistor 202-1 and capacitor 203-1 and a second memory cell comprises transistor 202-2 and capacitor 203-2. In this example, the memory array 230 is a DRAM array of 1T1C (one transistor one capacitor) memory cells; however, embodiments are not so limited. In a number of embodiments, the memory cells may be destructive read memory cells (e.g., reading the data stored in the cell destroys the data such that the data originally stored in the cell is refreshed after being read). The cells of the memory array 230 are arranged in rows coupled by word lines 204-X (Row X), 204-Y (Row Y), etc., and columns coupled by pairs of complementary data lines (e.g., DIGIT(n−1)/DIGIT(n−1)_, DIGIT(n)/DIGIT(n)_, DIGIT(n+1)/DIGIT(n+1)_). The individual data lines corresponding to each pair of complementary data lines can also be referred to as data lines 205-1 (D) and 205-2 (D_) respectively. Although only three pair of complementary data lines are shown in FIG. 2A, embodiments of the present disclosure are not so limited, and an array of memory cells can include additional columns of memory cells and/or data lines (e.g., 4,096, 8,192, 16,384, etc.).
Memory cells can be coupled to different data lines and/or word lines. For example, a first source/drain region of a transistor 202-1 can be coupled to data line 205-1 (D), a second source/drain region of transistor 202-1 can be coupled to capacitor 203-1, and a gate of a transistor 202-1 can be coupled to word line 204-Y. A first source/drain region of a transistor 202-2 can be coupled to data line 205-2 (D_), a second source/drain region of transistor 202-2 can be coupled to capacitor 203-2, and a gate of a transistor 202-2 can be coupled to word line 204-X. The cell plate, as shown in FIG. 2A, can be coupled to each of capacitors 203-1 and 203-2. The cell plate can be a common node to which a reference voltage (e.g., ground) can be applied in various memory array configurations.
The memory array 230 is coupled to sensing circuitry 250 in accordance with a number of embodiments of the present disclosure. In this example, the sensing circuitry 250 comprises a sense amplifier 206 and a compute component 231 corresponding to respective columns of memory cells (e.g., coupled to respective pairs of complementary data lines). The sense amplifier 206 can comprise a cross coupled latch, which can be referred to herein as a primary latch. The sense amplifier 206 can be configured, for example, as described with respect to FIG. 2B.
In the example illustrated in FIG. 2A, the circuitry corresponding to compute component 231 comprises a static latch 264 and an additional ten transistors that implement, among other things, a dynamic latch. The dynamic latch and/or static latch of the compute component 231 can be collectively referred to herein as a secondary latch, which can serve as an accumulator. As such, the compute component 231 can operate as and/or be referred to herein as an accumulator. The compute component 231 can be coupled to each of the data lines 205-1 (D) and 205-2 (_D) as shown in FIG. 2A. However, embodiments are not limited to this example. The transistors of compute component 231 can all be n-channel transistors (e.g., NMOS transistors); however, embodiments are not so limited.
In this example, data line 205-1 can be coupled to a first source/drain region of transistors 216-1 and 239-1, as well as to a first source/drain region of load/pass transistor 218-1. Data line 205-2 can be coupled to a first source/drain region of transistors 216-2 and 239-2, as well as to a first source/drain region of load/pass transistor 218-2.
The gates of load/pass transistor 218-1 and 218-2 can be commonly coupled to a LOAD control signal, or respectively coupled to a PASSD/PASSDB control signal, as discussed further below. A second source/drain region of load/pass transistor 218-1 can be directly coupled to the gates of transistors 216-1 and 239-2. A second source/drain region of load/pass transistor 218-2 can be directly coupled to the gates of transistors 216-2 and 239-1.
A second source/drain region of transistor 216-1 can be directly coupled to a first source/drain region of pull-down transistor 214-1. A second source/drain region of transistor 239-1 can be directly coupled to a first source/drain region of pull-down transistor 207-1. A second source/drain region of transistor 216-2 can be directly coupled to a first source/drain region of pull-down transistor 214-2. A second source/drain region of transistor 239-2 can be directly coupled to a first source/drain region of pull-down transistor 207-2. A second source/drain region of each of pull-down transistors 207-1, 207-2, 214-1, and 214-2 can be commonly coupled together to a reference voltage line 291-1 (e.g., ground (GND)). A gate of pull-down transistor 207-1 can be coupled to an AND control signal line, a gate of pull-down transistor 214-1 can be coupled to an ANDinv control signal line 213-1, a gate of pull-down transistor 214-2 can be coupled to an ORinv control signal line 213-2, and a gate of pull-down transistor 207-2 can be coupled to an OR control signal line.
The gate of transistor 239-1 can be referred to as node S1, and the gate of transistor 239-2 can be referred to as node S2. The circuit shown in FIG. 2A stores accumulator data dynamically on nodes S1 and S2. Activating the LOAD control signal causes load/pass transistors 218-1 and 218-2 to conduct, and thereby load complementary data onto nodes S1 and S2. The LOAD control signal can be elevated to a voltage greater than VDD to pass a full VDD level to S1/S2. However, elevating the LOAD control signal to a voltage greater than VDD is optional, and functionality of the circuit shown in FIG. 2A is not contingent on the LOAD control signal being elevated to a voltage greater than VDD.
The configuration of compute component 231 shown in FIG. 2A has the benefit of balancing the sense amplifier for functionality when the pull-down transistors 207-1, 207-2, 214-1, and 214-2 are conducting before the sense amplifier 206 is fired (e.g., during pre-seeding of the sense amplifier 206). As used herein, firing the sense amplifier 206 refers to enabling the sense amplifier 206 to set the primary latch and subsequently disabling the sense amplifier 206 to retain the set primary latch. Performing logical operations after equilibration is disabled (in the sense amp), but before the sense amplifier fires, can save power usage because the latch of the sense amplifier does not have to be “flipped” using full rail voltages (e.g., VDD, GND).
Inverting transistors can pull-down a respective data line in performing certain logical operations. For example, transistor 216-1 (having a gate coupled to S2 of the dynamic latch) in series with transistor 214-1 (having a gate coupled to an ANDinv control signal line 213-1) can be operated to pull-down data line 205-1 (D), and transistor 216-2 (having a gate coupled to S1 of the dynamic latch) in series with transistor 214-2 (having a gate coupled to an ANDinv control signal line 213-2) can be operated to pull-down data line 205-2 (D_).
The latch 264 can be controllably enabled by coupling to an active negative control signal line 212-1 (ACCUMB) and an active positive control signal line 212-2 (ACCUM) rather than be configured to be continuously enabled by coupling to ground and VDD. In various embodiments, load/pass transistors 208-1 and 208-2 can each having a gate coupled to one of a LOAD control signal or a PASSD/PASSDB control signal.
According to some embodiments, the gate of load/pass transistor 218-1 can be coupled to a PASSD control signal, and the gate of load/pass transistor 218-2 can be coupled to a PASSDb control signal. In the configuration in which the gates of transistors 218-1 and 218-2 are respectively coupled to one of the PASSD and PASSDb control signals, transistors 218-1 and 218-2 can be pass transistors. Pass transistors can be operated differently (e.g., at different times and/or under different voltage/current conditions) than load transistors. As such, the configuration of pass transistors can be different than the configuration of load transistors.
For instance, load transistors can be constructed to handle loading associated with coupling data lines to the local dynamic nodes S1 and S2, and pass transistors can be constructed to handle heavier loading associated with coupling data lines to an adjacent accumulator (e.g., through the shift circuitry 223, as shown in FIG. 2A). According to some embodiments, load/pass transistors 218-1 and 218-2 can be configured to accommodate the heavier loading corresponding to a pass transistor but be coupled and operated as a load transistor. Load/pass transistors 218-1 and 218-2 configured as pass transistors can also be utilized as load transistors. However, load/pass transistors 218-1 and 218-2 configured as load transistors may not be capable of being utilized as pass transistors.
In a number of embodiments, the compute component 231, including the latch 264, can comprise a number of transistors formed on pitch with the transistors of the corresponding memory cells of an array (e.g., array 230 shown in FIG. 2A) to which they are coupled, which may conform to a particular feature size (e.g., 4F2, 6F2, etc.). According to various embodiments, latch 264 includes four transistors 208-1, 208-2, 209-1, and 209-2 coupled to a pair of complementary data lines 205-1 and 205-2 through load/pass transistors 218-1 and 218-2. However, embodiments are not limited to this configuration. The latch 264 can be a cross coupled latch (e.g., gates of a pair of transistors, such as n-channel transistors (e.g., NMOS transistors) 209-1 and 209-2 are cross coupled with the gates of another pair of transistors, such as p-channel transistors (e.g., PMOS transistors) 208-1 and 208-2). As described further herein, the cross coupled latch 264 can be referred to as a static latch.
The voltages or currents on the respective data lines 205-1 and 205-2 can be provided to the respective latch inputs 217-1 and 217-2 of the cross coupled latch 264 (e.g., the input of the secondary latch). In this example, the latch input 217-1 is coupled to a first source/drain region of transistors 208-1 and 209-1 as well as to the gates of transistors 208-2 and 209-2. Similarly, the latch input 217-2 can be coupled to a first source/drain region of transistors 208-2 and 209-2 as well as to the gates of transistors 208-1 and 209-1.
In this example, a second source/drain region of transistor 209-1 and 209-2 is commonly coupled to a negative control signal line 212-1 (e.g., ground (GND) or ACCUMB control signal similar to control signal RnIF shown in FIG. 2B with respect to the primary latch). A second source/drain region of transistors 208-1 and 208-2 is commonly coupled to a positive control signal line 212-2 (e.g., VDD or ACCUM control signal similar to control signal ACT shown in FIG. 2B with respect to the primary latch). The positive control signal 212-2 can provide a supply voltage (e.g., VDD) and the negative control signal 212-1 can be a reference voltage (e.g., ground) to enable the cross coupled latch 264. According to some embodiments, the second source/drain region of transistors 208-1 and 208-2 are commonly coupled directly to the supply voltage (e.g., VDD), and the second source/drain region of transistor 209-1 and 209-2 are commonly coupled directly to the reference voltage (e.g., ground) so as to continuously enable latch 264.
The enabled cross coupled latch 264 operates to amplify a differential voltage between latch input 217-1 (e.g., first common node) and latch input 217-2 (e.g., second common node) such that latch input 217-1 is driven to either the activated positive control signal voltage (e.g., VDD) or the activated negative control signal voltage (e.g., ground), and latch input 217-2 is driven to the complementary (e.g., other) of the activated positive control signal voltage (e.g., VDD) or the activated negative control signal voltage (e.g., ground).
FIG. 2B illustrates a schematic diagram of a portion of a memory array in accordance with a number of embodiments of the present disclosure. According to various embodiments, sense amplifier 206 can comprise a cross coupled latch. However, embodiments of the sense amplifier 206 are not limited to a cross coupled latch. As an example, the sense amplifier 206 can be current-mode sense amplifier and/or single-ended sense amplifier (e.g., sense amplifier coupled to one data line). Also, embodiments of the present disclosure are not limited to a folded data line architecture.
In a number of embodiments, a sense amplifier (e.g., 206) can comprise a number of transistors formed on pitch with the transistors of the corresponding compute component 231 and/or the memory cells of an array (e.g., 230 shown in FIG. 2A) to which they are coupled, which may conform to a particular feature size (e.g., 4F2, 6F2, etc.). The sense amplifier 206 comprises a latch 215 including four transistors coupled to a pair of complementary data lines 205-1 and 205-2. The latch 215 can be a cross coupled latch (e.g., gates of a pair of transistors, such as n-channel transistors (e.g., NMOS transistors) 227-1 and 227-2 are cross coupled with the gates of another pair of transistors, such as p-channel transistors (e.g., PMOS transistors) 229-1 and 229-2). As described further herein, the latch 215 comprising transistors 227-1, 227-2, 229-1, and 229-2 can be referred to as a primary latch. However, embodiments are not limited to this example.
The voltages and/or currents on the respective data lines 205-1 and 205-2 can be provided to the respective latch inputs 233-1 and 233-2 of the cross coupled latch 215 (e.g., the input of the secondary latch). In this example, the latch input 233-1 is coupled to a first source/drain region of transistors 227-1 and 229-1 as well as to the gates of transistors 227-2 and 229-2. Similarly, the latch input 233-2 can be coupled to a first source/drain region of transistors 227-2 and 229-2 as well as to the gates of transistors 227-1 and 229-1. The compute component 231 (e.g., accumulator) can be coupled to latch inputs 233-1 and 233-2 of the cross coupled latch 215 as shown; however, embodiments are not limited to the example shown in FIG. 2B.
In this example, a second source/drain region of transistor 227-1 and 227-2 is commonly coupled to an active negative control signal 228 (RnIF). A second source/drain region of transistors 229-1 and 229-2 is commonly coupled to an active positive control signal 265 (ACT). The ACT signal 265 can be a supply voltage (e.g., VDD) and the RnIF signal can be a reference voltage (e.g., ground). Activating signals 228 and 265 enables the cross coupled latch 215.
The enabled cross coupled latch 215 operates to amplify a differential voltage between latch input 233-1 (e.g., first common node) and latch input 233-2 (e.g., second common node) such that latch input 233-1 is driven to one of the ACT signal voltage and the RnIF signal voltage (e.g., to one of VDD and ground), and latch input 233-2 is driven to the other of the ACT signal voltage and the RnIF signal voltage.
The sense amplifier 206 can also include circuitry configured to equilibrate the data lines 205-1 and 205-2 (e.g., in association with preparing the sense amplifier for a sensing operation). In this example, the equilibration circuitry comprises a transistor 224 having a first source/drain region coupled to a first source/drain region of transistor 225-1 and data line 205-1. A second source/drain region of transistor 224 can be coupled to a first source/drain region of transistor 225-2 and data line 205-2. A gate of transistor 224 can be coupled to gates of transistors 225-1 and 225-2.
The second source drain regions of transistors 225-1 and 225-2 are coupled to an equilibration voltage 238 (e.g., VDD/2), which can be equal to VDD/2, where VDD is a supply voltage associated with the array. The gates of transistors 224, 225-1, and 225-2 can be coupled to control signal 225 (EQ). As such, activating EQ enables the transistors 224, 225-1, and 225-2, which effectively shorts data line 205-1 to data line 205-2 such that the data lines 205-1 and 205-2 are equilibrated to equilibration voltage VDD/2. According to various embodiments of the present disclosure, a number of logical operations can be performed using the sense amplifier, and storing the result in the compute component (e.g., accumulator).
As shown in FIG. 2A, the sense amplifier 206 and the compute component 231 can be coupled to the array 230 via shift circuitry 223. In this example, the shift circuitry 223 comprises a pair of isolation devices (e.g., isolation transistors 221-1 and 221-2) coupled to data lines 205-1 and 205-2, respectively). The isolation transistors 221-1 and 221-2 are coupled to a control signal 222 (NORM) that, when activated, enables (e.g., turns on) the isolation transistors 221-1 and 221-2 to couple the corresponding sense amplifier 206 and compute component 231 to a corresponding column of memory cells (e.g., to a corresponding pair of complementary data lines 205-1 and 205-2. According to various embodiments, conduction of isolation transistors 221-1 and 221-2 can be referred to as a “normal” configuration of the shift circuitry 223.
In the example illustrated in FIG. 2A, the shift circuitry 223 includes another (e.g., a second) pair of isolation devices (e.g., isolation transistors 221-3 and 221-4) coupled to a complementary control signal 219 (SHIFT), which can be activated, for example, when NORM is deactivated. The isolation transistors 221-3 and 221-4 can be operated (e.g., via control signal 219) such that a particular sense amplifier 206 and compute component 231 are coupled to a different pair of complementary data lines (e.g., a pair of complementary data lines different than the pair of complementary data lines to which isolation transistors 221-1 and 221-2 couple the particular sense amplifier 206 and compute component 231), or can couple a particular sense amplifier 206 and compute component 231 to another memory array (and isolate the particular sense amplifier 206 and compute component 231 from a first memory array). According to various embodiments, the shift circuitry 223 can be arranged as a portion of (e.g., within) the sense amplifier 206, for instance.
Although the shift circuitry 223 shown in FIG. 2A includes isolation transistors 221-1 and 221-2 used to couple particular sensing circuitry 250 (e.g., a particular sense amplifier 206 and corresponding compute component 231) to a particular pair of complementary data lines 205-1 and 205-2 (e.g., DIGIT(n) and DIGIT(n)_) and isolation transistors 221-3 and 221-4 are arranged to couple the particular sensing circuitry 250 to an adjacent pair of complementary data lines in one particular direction (e.g., adjacent data lines DIGIT(n+1) and DIGIT(n+1)_ shown to the right in FIG. 2A), embodiments of the present disclosure are not so limited. For instance, shift circuitry can include isolation transistors 221-1 and 221-2 used to couple particular sensing circuitry to a particular pair of complementary data lines (e.g., DIGIT(n) and DIGIT(n)_ and isolation transistors 221-3 and 221-4 arranged so as to be used to couple the particular sensing circuitry to an adjacent pair of complementary data lines in another particular direction (e.g., adjacent data lines DIGIT(n−1) and DIGIT(n−1)_ shown to the left in FIG. 2A).
Embodiments of the present disclosure are not limited to the configuration of shift circuitry 223 shown in FIG. 2A. In a number of embodiments, shift circuitry 223 such as that shown in FIG. 2A can be operated (e.g., in conjunction with sense amplifiers 206 and compute components 231) in association with performing various operations (e.g., logical and/or arithmetic operations) without transferring data out of the sensing circuitry 250 via an I/O line (e.g., I/O line 334 shown in FIG. 3), for instance. Although shift circuitry 223 is shown to be separate from sensing circuitry 250 (e.g., sensing circuitry 150 in FIG. 1), shift circuitry 223 can be considered to be part of sensing circuitry 250 (e.g., sensing circuitry 150 in FIG. 1).
Although not shown in FIG. 2A, each column of memory cells can be coupled to a column decode line (e.g., decode lines 310-0 to 310-W shown in FIG. 3) that can be activated to transfer, via local I/O line (e.g., I/O line 334 shown in FIG. 3), a data value from a corresponding sense amplifier 206 and/or compute component 231 to a control component external to the array such as an external processing resource (e.g., host processor and/or other functional unit circuitry). The column decode line can be coupled to a column decoder (e.g., column decoder 152 shown in FIG. 1). However, as described herein, in a number of embodiments, data need not be transferred via such I/O lines to perform logical operations in accordance with embodiments of the present disclosure. In a number of embodiments, shift circuitry 223 can be operated in conjunction with sense amplifiers 206 and compute components 231 to perform various operations (e.g., logical operations in association with performing subtraction, addition, multiplication, division, etc.) without transferring data to a control component external to the array, for instance.
The sensing circuitry 250 can be operated in several modes to perform logical operations, including a second mode in which a result of the logical operation is initially stored in the sense amplifier 206, and a first mode in which a result of the logical operation is initially stored in the compute component 231. Operation of the sensing circuitry 250 in the second mode is described below with respect to FIGS. 5 and 6, and operation of the sensing circuitry 250 in the second mode is described below with respect to FIGS. 7-10. Additionally with respect to the first operating mode, sensing circuitry 250 can be operated in both pre-sensing (e.g., sense amps fired before logical operation control signal active) and post-sensing (e.g., sense amps fired after logical operation control signal active) modes with a result of a logical operation being initially stored in the sense amplifier 206.
As described further below, the sense amplifier 206 can, in conjunction with the compute component 231, be operated to perform various logical operations using data from an array as input. In a number of embodiments, the result of a logical operation can be stored back to the array without transferring the data via a data line address access (e.g., without firing a column decode signal such that data is transferred to circuitry external from the array and sensing circuitry via local I/O lines). As such, a number of embodiments of the present disclosure can enable performing logical operations using less power than various previous approaches. Additionally, since a number of embodiments eliminate the need to transfer data across I/O lines (e.g., between memory and discrete processor) in order to perform various operations (e.g., compute functions), a number of embodiments can enable an increased parallel processing capability as compared to previous approaches.
FIG. 3 illustrates a schematic diagram of a portion of a memory array 330 in accordance with a number of embodiments of the present disclosure. The array 330 can include memory cells 303-0, 303-1, 303-3, 303-4, 303-5, 303-6, 303-7, 303-8, . . . , 303-J (e.g., referred to generally as memory cells 303), coupled to rows of access lines 304-0, 304-1, 304-2, 304-3, 304-4, 304-5, 304-6, . . . , 304-R and columns of sense lines 305-0, 305-1, 305-2, 305-3, 305-4, 305-5, 305-6, 305-7, . . . , 305-S, which may be referred to generally as access lines 304 and sense lines 305. Memory array 330 is not limited to a particular number of access lines and/or sense lines, and use of the terms “rows” and “columns” does not intend a particular physical structure and/or orientation of the access lines and/or sense lines. Although not pictured, each column of memory cells can be associated with a corresponding pair of complementary sense lines (e.g., complementary sense lines 205-1 and 205-2 in FIG. 2A).
Each column of memory cells can be coupled to sensing circuitry (e.g., sensing circuitry 150 shown in FIG. 1 and sensing circuitry 250 shown in FIG. 2A). In this example, the sensing circuitry comprises a number of sense amplifiers 306-0, 306-1, 306-2, 306-3, 306-4, 306-5, 306-6, 306-7, . . . , 306-U (e.g., referred to generally as sense amplifiers 306) coupled to the respective sense lines 305-0, 305-1, 305-2, 305-3, 305-4, 305-5, 305-6, 305-7, . . . , 305-S. The sense amplifiers 306 are coupled to input/output (I/O) line 334 (e.g., a local I/O line) via access devices (e.g., transistors) 308-0, 308-2, 308-3, 308-4, 308-5, 308-6, 308-7, . . . , 308-V. In this example, the sensing circuitry also comprises a number of compute components 331-0, 331-2, 331-3, 331-4, 331-5, 331-6, 331-7, . . . , 331-X (e.g., referred to generally as compute components 331) coupled to the respective sense lines. Column decode lines 310-0 to 310-W are coupled to the gates of transistors 308-0 to 308-V, respectively, and can be selectively activated to transfer data sensed by respective sense amplifiers 306-0 to 306-U and/or stored in respective compute components 331-0 to 331-X to a secondary sense amplifier 312 and/or to processing resources external to array 330 (e.g., via I/O line 334). In a number of embodiments, the compute components 331 can be formed on pitch with the memory cells of their corresponding columns and/or with the corresponding sense amplifiers 306.
The sensing circuitry (e.g., compute components 331 and sense amplifiers 306) is configured to perform a swap operation in accordance with a number of embodiments described herein. The example described in association with FIGS. 4A to 4Q demonstrates how a swap operation can be performed on elements stored in an array such as array 330. As described below, the elements can be stored such that each of a number of elements (e.g., data corresponding to logic “1” or logic “0”) are stored in memory cells commonly coupled to one of a respective number sense lines (e.g., 305-0 to 305-S). For example, a first element can be stored in a group of memory cells coupled to sense line 305-0, as second element can be stored in a group of memory cells coupled to sense line 305-1, etc.). In a number of embodiments, a swap operation can be performed on selected adjacent element pairs (e.g., selected element pairs each comprising a first element stored in memory cells coupled to an even numbered sense line and a second element stored in memory cells coupled to an adjacent odd numbered sense line). The elements being swapped can also be commonly coupled to a number of access lines (e.g., 304-0 to 304-R). For instance, consider six elements each stored in a group of three memory cells commonly coupled to one of sense lines 305-0 to 305-5. In this example, a first memory cell corresponding to each of the respective elements can be commonly coupled to a first access line (e.g., 304-0), a second memory cell corresponding to each of the respective elements can be commonly coupled to a second access line (e.g., 304-1), and a third memory cell corresponding to each of the respective elements can be commonly coupled to a third access line (e.g., 304-2).
FIGS. 4A-4Q illustrate the states (e.g., logic values) of memory cells of a portion of an array 430 at a number of particular phases associated with performing a swap operation in accordance with a number of embodiments of the present disclosure. The array 430 can be an array such as array 330 described in FIG. 3. FIGS. 4A-4Q illustrate the states (e.g., logic “1” or logic “0”) of the cells coupled to a number of access lines 404-0 (Row 0), 404-1 (Row 1), 404-2 (Row 2), 404-3 (Mask Row), 404-4 (Shifted Mask Row), 404-5 (Temp Row 1), and 404-6 (Temp Row 2) and to a number of sense lines 405-0 (Col 0), 405-1 (Col 1), 405-2 (Col 2), 405-3 (Col 3), 405-4 (Col 4), and 405-5 (Col 5). FIGS. 4A-4Q also illustrate the states of sensing circuitry 450 (e.g., compute components 331 and/or sense amplifiers 306 shown in FIG. 3) coupled to the respective sense lines 405-0 to 405-5 during various phases of a swap operation (e.g., various phases associated with executing the example psuedocode described below).
The example of FIGS. 4A-4Q can include six elements each stored in a group of memory cells commonly coupled to one of sense lines 405-0 to 405-5. The six elements are values (e.g., decimal values) and are stored as binary bit-vectors 488-0, 488-1, 488-2, 488-3, 488-4, and 488-5 (referred to generally as bit-vectors 488) in array 430. In this example, each of the elements is stored in three memory cells coupled to a particular sense line and to access lines 404-0, 404-1, and 404-2. For instance, the element represented by bit-vector 488-0 (e.g., [011]) is stored in the memory cells coupled to sense line 405-0 and to access lines 404-0 to 404-2, the element represented by bit-vector 488-1 (e.g., [001]) is stored in the memory cells coupled to sense line 405-1 and to access lines 404-0 to 404-2, the element represented by bit-vector 488-2 (e.g., [010]) is stored in the memory cells coupled to sense line 405-2 and to access lines 404-0 to 404-2, the element represented by bit-vector 488-3 (e.g., [100]) is stored in the memory cells coupled to sense line 405-3 and to access lines 404-0 to 404-2, the element represented by bit-vector 488-4 (e.g., [100]) is stored in the memory cells coupled to sense line 405-4 and to access lines 404-0 to 404-2, and the element represented by bit-vector 488-5 (e.g., [010]) is stored in the memory cells coupled to sense line 405-5 and to access lines 404-0 to 404-2. FIGS. 4A-4Q also indicate the values (e.g., decimal values) 489-0 to 489-5 (referred to generally as values 489) of the elements represented by respective bit-vectors 488-0 to 488-5. For instance, as shown in FIG. 4A, bit-vector 488-0 (e.g., [011]) corresponds to value 489-0 (e.g., a decimal value of 3), bit-vector 488-1 (e.g., [001]) corresponds to value 489-1 (e.g., a decimal value of 1), bit-vector 488-2 (e.g., [010]) corresponds to value 489-2 (e.g., a decimal value of 2), bit-vector 488-3 (e.g., [100]) corresponds to value 489-3 (e.g., a decimal value of 4), bit-vector 488-4 (e.g., [100]) corresponds to value 489-4 (e.g., a decimal value of 4), and bit-vector 488-5 (e.g., [010]) corresponds to value 489-5 (e.g., a decimal value of 2).
Although, in the example of FIGS. 4A-4Q, the elements are stored in three cells coupled to respective sense lines such that they are represented by 3-bit bit-vectors, embodiments are not so limited. For instance, the elements can be stored in more or fewer than three cells. Also, in FIGS. 4A-4Q, the LSB (least significant bit) of the bit-vectors 488-0 to 488-5 is stored in cells coupled to access line 404-0, the next LSB is stored in cells coupled to access line 404-1, and the MSB (most significant bit) is stored in cells coupled to access line 404-2; however, embodiments are not limited to a particular ordering of bits. Also, a plurality of elements can be represented by a particular bit-vector (e.g., 488-0 to 488-5). For instance, sense line 405-0 can be coupled to memory cells that store multiple elements that can be swapped with corresponding elements stored in memory cells coupled to a different sense line (e.g., 405-1).
The example described in FIGS. 4A-4Q involves swapping selected adjacent element pairs (e.g., selected element pairs each comprising an element stored in the cells coupled to a particular sense line and an element stored in the cells coupled to an adjacent sense line). Specifically, the example of FIGS. 4A-4Q involves swapping the elements stored as bit-vectors 488-0 and 488-1 (e.g., a first element pair) and swapping the elements stored as bit-vectors 488-2 and 488-3 (e.g., a second element pair). In this example, the elements stored as bit-vectors 488-4 and 488-5 (e.g., a third element pair) are not swapped. As such, the swapping operation described in association with FIGS. 4A-4Q results in the element originally stored in the cells coupled to sense line 405-0 (e.g., bit-vector [011] representing a decimal value of 3) being stored in the cells coupled to sense line 405-1, and the element originally stored in the cells coupled to sense line 405-1 (e.g., bit-vector [001] representing a decimal value of 1) being stored in the cells coupled to sense line 405-0, such that subsequent to swapping, bit-vector 488-0 is [001] and bit-vector 488-1 is [011]. Similarly, the swapping operation described in association with FIGS. 4A-4Q results in the element originally stored in the cells coupled to sense line 405-2 (e.g., bit-vector [010] representing a decimal value of 2) being stored in the cells coupled to sense line 405-3, and the element originally stored in the cells coupled to sense line 405-3 (e.g., bit-vector [100] representing a decimal value of 4) being stored in the cells coupled to sense line 405-2, such that subsequent to swapping, bit-vector 488-2 is [100] and bit-vector 488-3 is [010]. In a number of embodiments, the swapping operation can be performed such that swapping of the element pairs being swapped occurs in parallel.
In a number of embodiments, the states of the memory cells commonly coupled to a particular access line (404) represent a stored data pattern (e.g., bit pattern) corresponding to a bit-vector. For instance, in the example of FIGS. 4A-4Q, the memory cells commonly coupled to access line 404-0 (Row 0) and to sense lines 405-0 to 405-5 represent a stored data pattern corresponding to bit-vector 474-0 (e.g., [110000] as shown in FIG. 4A), which may be referred to as the “Row 0 bit-vector.” The memory cells commonly coupled to access line 404-1 (Row 1) and to sense lines 405-0 to 405-5 represent a stored data pattern corresponding to bit-vector 474-1 (e.g., [101001] as shown in FIG. 4A), which may be referred to as the “Row 1 bit-vector.” The memory cells commonly coupled to access line 404-2 (Row 2) and to sense lines 405-0 to 405-5 represent a stored data pattern corresponding to bit-vector 474-2 (e.g., [000110] as shown in FIG. 4A), which may be referred to as the “Row 2 bit-vector.” As such, bit-vector 474-0 comprises the LSBs of the respective bit-vectors 488, bit-vector 474-1 comprises the next LSBs of the respective bit-vectors 488, and bit-vector 474-2 comprises the MSBs of the respective bit-vectors 488 (e.g., the bit-vectors representing the elements corresponding to the respective sense lines 405-0 to 405-5). In this example, the LSB of the bit-vectors 488 can be associated with an index of “0” (e.g., n=0), the next LSB of the bit-vectors 488 can be associated with an index of “1” (e.g., n=1), and the MSB of the bit-vectors 488 can be associated with an index of “2” (e.g., n=2).
In a number of embodiments, groups of memory cells in addition to those storing elements (e.g., the elements represented by the bit-vectors 488) can be used to perform a swapping operation. The additional groups of memory cells can be groups of memory cells commonly coupled to respective access lines and to the sense lines corresponding to the stored elements (e.g., sense lines 405-0 to 405-5 in the example of FIGS. 4A-4Q). As an example, a first additional group of memory cells can be used to store a bit pattern that can serve as a mask that can define which element pairs are being swapped. In the example shown in FIGS. 4A-4Q, the cells coupled to access line 404-3 (Mask Row) and to sense lines 405-0 to 405-5 serve as a mask that can define which of the element pairs are being swapped. The states of the memory cells of Mask Row 404-3 represent a stored data pattern corresponding to bit-vector 476, which can be referred to as the “Mask Row bit-vector.” A second additional group of memory cells can also be used to store a bit pattern that can serve as a mask in association with performing a swap operation. In the example shown in FIGS. 4A-4Q, the cells coupled to access line 404-4 (Shifted Mask Row) and to sense lines 405-0 to 405-5 serve as a mask during a swap operation. The states of the memory cells of Shifted Mask Row 404-4 represent a stored data pattern corresponding to bit-vector 478, which can be referred to as the “Shifted Mask Row bit-vector.” In this example, and as shown in FIG. 4B, the data pattern corresponding to the Shifted Mask Row bit-vector is the data pattern corresponding to the Mask Row bit-vector shifted one bit-position to the right. A number of additional groups of memory cells can be used as temporary storage in association with performing a swapping operation. The example shown in FIGS. 4A-4Q can include an additional group of memory cells coupled to access line 404-5 (Temp Row 1) and to sense lines 405-0 to 405-5 that is used as temporary storage and an additional group of cells coupled to access line 404-6 (Temp Row 2) and to sense lines 405-1 to 405-5 that is used as temporary storage. The states of the memory cells of Temp Row 1 404-5 represent a stored data pattern corresponding to bit-vector 480, which can be referred to as the “Temp Row 1 bit-vector,” and the states of the memory cells of Temp Row 2 404-6 represent a stored data pattern corresponding to bit-vector 482, which can be referred to as the “Temp Row 2 bit-vector.” In a number of embodiments, the Mask Row 404-3, Shifted Mask Row 404-4, Temp Row 1 404-5, and Temp Row 2 404-6 may not be addressable to a user (e.g., the cells coupled to those access lines may not be part of the addressable space of the array 430).
FIGS. 4A-4Q also illustrate the states of sensing circuitry 450 (e.g., compute components 331 and/or sense amplifiers 306 shown in FIG. 3) coupled to the respective sense lines 405-0 to 405-5 during various phases of a swap operation. The states (e.g., latched logic values) of the sensing circuitry 450 represent a stored data pattern corresponding to bit-vector 483.
As described below, in a number of embodiments, swapping selected elements stored in an array (e.g., array 430) can include performing a number of logical operations such as AND, OR, NOT, NAND, NOR, and/or shift operations. The logical operations can be performed using data stored in the array as inputs, and can be performed without transferring data from the array via an I/O line, for instance. In a number of embodiments, the bit-vectors 474-0, 474-1, 474-2, 476, 478, 480, 482, and 483 serve as operands to the logical operations in association with swapping the selected elements.
The below pseudocode represents instructions executable to perform a number of swap operations in a memory in accordance with a number of embodiments of the present disclosure. The example pseudocode is referenced using reference numbers 1-4. For example, reference number one (1) corresponds to “readRow(Mask Row)” as shown in the below pseudocode, reference number two (2) corresponds to “shift(RIGHT)” as shown in the below pseudocode, etc.
















1.
readRow(Mask Row);



2.
shift(RIGHT);



3.
writeRow(Shifted Mask Row);



4.
for (n = 0; n < element width; n++) do:










a.
readRow(Row(n));



b.
writeRow(Temp Row 1);



c.
shift(RIGHT);



d.
andRow(Shifted Mask Row);



e.
writeRow(Temp Row 2);



f.
readRow(Shifted Mask Row);



g.
inv( );



h.
andRow(Row(n));



i.
orRow(Temp Row 2);



j
writeRow(Row(n));



k.
readRow(Temp Row 1);



l.
andRow(Shifted Mask Row);



m.
shift(LEFT);



n.
writeRow(Temp Row 2);



o.
readRow(Mask Row);



p.
inv( );



q.
andRow(Row(n));



r.
orRow(Temp Row 2);



s.
writeRow(Row(n));










For purposes of discussion, the above pseudocode will be divided into a setup phase and an iterations phase. In this example, FIGS. 4A and 4B and the pseudocode referenced by reference numbers 1-3 corresponds to the setup phase.
FIGS. 4C to 4Q and the pseudocode referenced by reference number 4 (e.g., 4.a-4.s) corresponds to the iterations phase. Each of the iterations (e.g., of the “For” loop) associated with the iterations phase can further be divided into a first phase, a second phase, a third phase, a fourth phase, and a fifth phase, with the first phase corresponding to the pseudocode referenced by reference numbers 4.a and 4.b, the second phase corresponding to the pseudocode referenced by reference numbers 4.c to 4.e, the third phase corresponding to the pseudocode referenced by reference numbers 4.f to 4.j, the fourth phase corresponding to the pseudocode referenced by reference numbers 4.k to 4.n, and the fifth phase corresponding to the pseudocode referenced by reference numbers 4.o to 4.s. The data patterns corresponding to bit-vectors 474-0, 474-1, 474-2, 476, 478, 480, 482, and 483 during execution of the iterations phase are shown in FIGS. 4C to 4S.
The iterations phase can include performing a number of iterations of operations. For example, the pseudocode corresponding to reference number 4 (e.g., for (n=0; n<element width; n++) do:) represents a “For” loop associated with an index n. The index n can initially be set to zero (e.g., n=0) and incremented (e.g., n++) after each iteration (e.g., after each iteration of the “For” loop). In this example, the “For” loop terminates when the value of n is equal to a width of the bit-vectors 488 representing elements being swapped (e.g., when n=3, in this example). As such, the number of times the “For” loop is performed (e.g., the number of iterations) is equal to the width of the bit-vectors 488 (e.g., 3 bits in this example). Embodiments are not limited to a particular type of loop structure. For example, reference number 4 can represent a “while” loop, among other possible loop structures.
As described further below, in this example, FIGS. 4C-4G correspond to a first iteration of the iterations phase (e.g., an initial execution of the “For” loop corresponding to the pseudocode referenced by 4.a to 4.s), FIGS. 4H-4L correspond to a second iteration of the iterations phase, and FIGS. 4M-4Q correspond to a third iteration of the iterations phase.
As described above, FIG. 4A illustrates a number of elements stored as bit-vectors 488-0 to 488-5 in array 430 (e.g., prior to a swap operation). The Mask Row bit-vector 476 can define selected adjacent element pairs to be swapped. The Mask Row bit-vector 476 can be provided from a host, for instance. In this example, the element pairs to be swapped can be defined by whether or not the cells of Mask Row 404-3 coupled to even numbered sense lines store a logic “1.” For instance, a logic “1” in a bit position of bit-vector 476 corresponding to an even numbered sense line indicates that the corresponding element (e.g., the element stored in cells coupled to the particular even numbered sense line) is to be swapped with an adjacent element (e.g., the element stored in cells coupled to the adjacent odd numbered sense line). For instance, in FIG. 4A, bit-vector 476 is [101000], which indicates that a “1” is stored in cells corresponding to even numbered sense lines 405-0 and 405-2, and that a “0” is stored in the cell corresponding to even numbered sense line 405-4. As such, Mask Row bit-vector 476 defines the element pairs being swapped as being the elements coupled to sense lines 405-0 and 405-1, and the elements coupled to sense lines 405-2 and 405-3 (e.g., the element initially stored in cells coupled to sense line 405-0 is swapped with the element initially stored in cells coupled to sense line 405-1, and the element initially stored in cells coupled to sense line 405-2 is swapped with the element initially stored in cells coupled to sense line 405-3). As used herein, “even swap elements” can refer to elements to be swapped and which are stored in cells coupled to even numbered sense lines (e.g., even numbered columns), and “odd swap elements” can refer to the corresponding adjacent elements to be swapped and which are stored in cells coupled to odd numbered sense lines (e.g., odd numbered columns). As such, in this example, the elements represented by bit-vectors 488-0 and 488-2 can be referred to as the even swap elements, and the elements represented by bit-vectors 488-1 and 488-3 can be referred to as the odd swap elements.
In FIGS. 4A to 4Q changes to the states of memory cells corresponding to the bit-vectors 474-0, 474-1, 474-2, 476, 478, 480, 482, and 483 are indicated in bold font. For example, in FIG. 4B the data pattern corresponding to bit-vector 478 (e.g., the memory cells coupled to access line 404-4 and to sense lines 405-0 to 405-5) is shown in bold font to indicate the logic values corresponding to bit-vector 476 have changed during a phase of the swap operation.
The setup phase of the swap operation described in association with FIGS. 4A-4Q can include execution of the pseudocode corresponding to reference numbers 1-3. The pseudocode corresponding to reference numbers 1-3 is associated with generating a shifted mask and storing it in the array 430 (e.g., storing it in Shifted Mask Row 404-4 as bit-vector 478). The shifted mask can be used to isolate odd swap elements (e.g., the elements corresponding to odd numbered sense lines 405-1 and 405-3 and represented by respective bit-vectors 488-1 and 488-3, in this example).
The pseudocode corresponding to reference number 1 (e.g., “readRow(Mask Row)”) involves reading the data pattern stored as Mask Row bit-vector 476 (e.g., [101000]) into the sensing circuitry 450 (e.g., compute components 331-0 to 331-5 and/or sensing amplifiers 306-0 to 306-5) corresponding to bit-vector 483. As used herein, storing a bit-vector in the sensing circuitry is defined as storing the bit-vector in a number of compute components associated with the sensing circuitry and/or in a number of sense amplifiers associated with the sensing circuitry.
The pseudocode corresponding to reference number 2 (e.g., “shift(RIGHT)”), is associated with performing a SHIFT operation on the bit-vector 483. The SHIFT operation shifts bits stored in the sensing circuitry 450 one bit position to the right. In this example, prior to the SHIFT operation, the bit-vector 483 is [101000](e.g., the data pattern corresponding to Mask Row bit-vector 476 which was read into the sensing circuitry 450 corresponding to bit-vector 483). After the SHIFT operation and as shown in FIG. 4B, the bit-vector 483 is [010100].
The pseudocode corresponding to reference number 3 (e.g., “writeRow(Temp Row 1)”), is associated with writing the data pattern stored in sensing circuitry 450 (e.g., as bit-vector 483) to the cells storing the Shifted Mask Row bit-vector 478. As described further below, the data pattern corresponding to bit-vector 483 can be copied from the sensing circuitry 450 to the cells storing bit-vector 478 (e.g., the cells coupled to access line 404-4) by activating access line 404-4, for instance. As shown in FIG. 4B, the data pattern corresponding to bit-vector 483 (e.g., [010100]), which is the result of the SHIFT operation performed on the data pattern corresponding to bit-vector 476 (e.g., [101000]), is stored in the memory cells corresponding to Shifted Mask Row 478. For instance, Shifted Mask Row bit-vector 478 is [010100].
FIGS. 4C-4G correspond to a first iteration of the iterations phase (e.g., an initial execution of the “For” loop corresponding to the pseudocode referenced by 4.a to 4.s and for which the index n is 0). A first phase of the first iteration corresponds to the pseudocode referenced by reference numbers 4.a and 4.b and FIG. 4C, and is associated with storing the data pattern of the “Row n bit-vector” in the cells corresponding to the Temp Row 1 bit-vector 480. For instance, a copy of the data stored in a first row of cells comprising data to be swapped (e.g., cells coupled to access line 404-0) is stored in the cells corresponding to Temp Row 1 bit-vector 480. For this iteration (e.g., the first iteration), the index “n” is 0 (e.g., n=0 for the first iteration of the “For” loop). At reference number 4.a of the pseudocode (e.g., “readRow(Row(n))”), the data pattern corresponding to the “Row n bit-vector” is read into the sensing circuitry corresponding to bit-vector 483. Since n=0 for the first iteration of the “For” loop, the data pattern corresponding to the Row 0 bit-vector 474-0 (e.g., [110000]) is read into the sensing circuitry 450, such that bit-vector 483 is [110000], as shown in FIG. 4C. At reference number 4.b (e.g., “writeRow(Temp Row 1)”), the data pattern corresponding to bit-vector 483 is copied to the cells storing the Temp Row 1 bit-vector 480. As such, Temp Row 1 bit-vector 480 is [110000] as shown in FIG. 4C.
FIG. 4D and the pseudocode referenced by reference numbers 4.c-4.e corresponds to a second phase of the iterations phase and is associated with performing a shift operation on the bit-vector 483, “ANDing” the shifted bit-vector with the Shifted Mask Row bit-vector 478, and storing the resultant data pattern to the cells corresponding to Temp Row 2 bit-vector 482. At reference number 4.c of the pseudocode (e.g., “shift(RIGHT)”), the data pattern stored as bit-vector 483 is shifted one bit-position to the right, such that bit-vector 483 is [011000], which is the previous bit-vector 483 (e.g., [110000]) shifted right one bit position. At reference number 4.d (e.g., “andRow(Shifted Mask Row)”), an AND operation is performed on bit-vector 478 (e.g., [010100]) and bit-vector 483 (e.g., [011000]).
As used herein, performing a logical operation on a first and second bit-vector can include performing, in parallel, the logical operation on each of the respective bits at corresponding bit positions of the bit-vectors. As an example, the result of a logical OR operation performed on a first bit-vector “a” (e.g., [a0 a1 a2 a3]) and a second bit-vector “b” (e.g., [b0 b1 b2 b3]) is a bit-vector “c” (e.g., [c0 c1 c2 c3]), wherein c0=a0 OR b0, c1=a1 OR b1, c2=a2 OR b2, and c3=a3 OR b3. For instance, performing an OR operation on a bit-vector [1110] and on bit-vector [1000] would result in bit-vector [1110](e.g., the leftmost bit of the resultant bit-vector is “1” since “1” OR “1” is “1”, the next bit is “1” since “1” OR “0” is “1”, the next bit is “1” since “1” OR “0” is “1”, and the rightmost bit is “0” since “0” OR “0” is “0”).
In this example, “ANDing” bit-vectors 478 and 483 (e.g., [010100] AND [011000]) results in [010000] being stored as bit-vector 483 (e.g., the result of the AND operation is stored in the sensing circuitry 450). As such, bit-vector 483 is [010000] as shown in FIG. 4D. At reference number 4.e (e.g., “writeRow(Temp Row 2)”), the data pattern corresponding to bit-vector 483 is copied to the cells storing the Temp Row 2 bit-vector 482. As such, Temp Row 2 bit-vector 482 is [010000] as shown in FIG. 4D. It is noted that the same result for the second phase can be obtained by “ANDing” the bit-vector 483 (which stores the data pattern corresponding to the Row 0 bit-vector 474-0) with Mask Row bit-vector 476, and then performing a right shift on bit-vector 483 prior to copying to Temp Row 2 bit-vector 482.
FIG. 4E and the pseudocode referenced by reference numbers 4.f-4.j corresponds to a third phase of the iterations phase and is associated with performing an invert operation on the data pattern corresponding to the Shifted Mask Row bit-vector 478, performing an AND operation on the result of the invert operation and the Row n bit-vector (e.g., 474-0 for this iteration), performing an OR operation on the result of the AND operation and the Temp Row 2 bit-vector 482, and writing the result of the OR operation back to the cells storing the Row n bit-vector. At reference number 4.f of the pseudocode (e.g., “readRow(Shifted Mask Row)”), the data pattern stored as bit-vector 478 is read into the sensing circuitry 450 such that bit-vector 483 is [010100]. At reference number 4.g (e.g., “inv( )”), an invert operation is performed on bit-vector 483 such that bit-vector 483 stores [101011](e.g., the inverse of its previous data pattern). At reference number 4.h (e.g., “andRow(Row(n))”), an AND operation is performed on the bit-vector 483 (e.g., [101011]) and bit-vector 474-0 (e.g., [110000]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [100000]. The result of the AND operation (e.g., [100000]), which is stored as bit-vector 483, is ORed with the Temp Row 2 bit-vector 482 (e.g., [010000]), with the result (e.g., [110000]) being retained in sensing circuitry 450 as bit-vector 483. The result of the OR operation (e.g., [110000]) is copied to the cells storing bit-vector 474-0. As such, as shown in FIG. 4E, bit-vectors 474-0 and 483 are [110000] after the third phase.
FIG. 4F and the pseudocode referenced by reference numbers 4.k-4.n corresponds to a fourth phase of the iterations phase and is associated with performing an AND operation on the Shifted Mask Row bit-vector 478 and the Temp Row 1 bit-vector 480, shifting the result of the AND operation one bit position to the left, and writing the result of the left shift to the cells storing Temp Row 2 bit-vector 482. At reference number 4.k of the pseudocode (e.g., “readRow(Temp Row 1)”), the data pattern stored as bit-vector 480 is read into the sensing circuitry 450 such that bit-vector 483 is [110000]. At reference number 4.l (e.g., “andRow(Shifted Mask Row)”), an AND operation is performed on the bit-vector 483 (e.g., [110000]) and bit-vector 478 (e.g., [010100]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [010000]. At reference number 4.m (e.g., “shift(LEFT)”), the result of the AND operation (e.g., [010000]), which is stored as bit-vector 483, is shifted one bit position to the left, such that bit-vector 483 is [100000]). At reference number 4.n (e.g., “writeRow(Temp Row 2)”), the result of the left shift operation (e.g., [100000]) is copied to the cells storing bit-vector 482. As such, as shown in FIG. 4F, bit-vectors 482 and 483 are [100000] after the fourth phase.
FIG. 4G and the pseudocode referenced by reference numbers 4.o-4.s corresponds to a fifth phase of the iterations phase and is associated with performing an invert operation on the data pattern corresponding to the Mask Row bit-vector 476, performing an AND operation on the result of the invert operation and the Row n bit-vector (e.g., 474-0 for this iteration), performing an OR operation on the result of the AND operation and the Temp Row 2 bit-vector 482, and writing the result of the OR operation back to the cells storing the Row n bit-vector. At reference number 4.o of the pseudocode (e.g., “readRow(Mask Row)”), the data pattern stored as bit-vector 476 is read into the sensing circuitry 450 such that bit-vector 483 is [101000]. At reference number 4.p (e.g., “inv( )”), an invert operation is performed on bit-vector 483 such that bit-vector 483 stores [0101111](e.g., the inverse of its previous data pattern). At reference number 4.q (e.g., “andRow(Row(n))”), an AND operation is performed on the bit-vector 483 (e.g., [010111]) and bit-vector 474-0 (e.g., [110000]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [010000]. The result of the AND operation (e.g., [010000]), which is stored as bit-vector 483, is ORed with the Temp Row 2 bit-vector 482 (e.g., [100000]), with the result (e.g., [110000]) being retained in sensing circuitry 450 as bit-vector 483. The result of the OR operation (e.g., [110000]) is copied to the cells storing bit-vector 474-0. As such, as shown in FIG. 4G, bit-vectors 474-0 and 483 are [110000] after the fifth phase.
FIG. 4G shows the states of memory cells of array 430 after a first iteration of a “For” loop associated with reference number 4. After a first iteration of the “For” loop, the 1-bit from bit-vector 488-0 (e.g., a bit-vector [011]) is swapped with a 1-bit from bit-vector 488-1 (e.g., a bit-vector [001]) and the 0-bit from bit-vector 488-2 (e.g., a bit-vector [010]) is swapped with a 0-bit from bit-vector 488-3 (e.g., a bit-vector [100]). FIGS. 4H to 4L show the state of memory cells of array 430 after a second iteration of a “For” loop associated with reference number 4.
FIGS. 4H-4L correspond to a second iteration of the iterations phase. For this iteration (e.g., the second iteration), the index “n” is 1 (e.g., n=1 for the second iteration of the “For” loop). A first phase of the second iteration corresponds to the pseudocode referenced by reference numbers 4.a and 4.b and FIG. 4H. At reference number 4.a of the pseudocode (e.g., “readRow(Row(n))”), the data pattern corresponding to the “Row n bit-vector” is read into the sensing circuitry corresponding to bit-vector 483. Since n=1 for the second iteration of the “For” loop, the data pattern corresponding to the Row 1 bit-vector 474-1 (e.g., [101001]) is read into the sensing circuitry 450, such that bit-vector 483 is [101001], as shown in FIG. 4H. At reference number 4.b, the data pattern corresponding to bit-vector 483 is copied to the cells storing the Temp Row 1 bit-vector 480. As such, Temp Row 1 bit-vector 480 is [101001] as shown in FIG. 4H. At reference number 4.b, Temp Row 1 bit-vector 480 is [101001] as shown in FIG. 4H.
FIG. 4I and the pseudocode referenced by reference numbers 4.c-4.e corresponds to a second phase of the second iteration. At reference number 4.c, the data pattern stored as bit-vector 483 is shifted one bit-position to the right, such that bit-vector 483 is [010100], which is the previous bit-vector 483 (e.g., [101001]) shifted right one bit position. At reference number 4.d, an AND operation is performed on bit-vector 478 (e.g., [010100]]) and bit-vector 483 (e.g., [010100]). The result (e.g., [010100]) of the AND operation is stored in the sensing circuitry 450 as bit-vector 483. As such, bit-vector 483 is [010100] as shown in FIG. 4I. At reference number 4.e, bit-vector 483 is copied to the memory cells that store Temp Row 2 bit-vector 482. As such Temp Row 2 bit-vector 482 is [010100] as shown in FIG. 4I.
FIG. 4J and the pseudocode referenced by reference numbers 4.f-4.j corresponds to a third phase of the second iteration. At reference number 4.f, the data pattern stored as bit-vector 478 is read into the sensing circuitry 450 such that bit-vector 483 is [010100]. At reference number 4.g (e.g., “inv( )”), an invert operation is performed on bit-vector 483 such that bit-vector 483 stores [101011](e.g., the inverse of its previous data pattern). At reference number 4.h, an AND operation is performed on the bit-vector 483 (e.g., [101011]) and bit-vector 474-1 (e.g., [101001]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [101001]. The result of the AND operation (e.g., [101001]), which is stored as bit-vector 483, is ORed with the Temp Row 2 bit-vector 482 (e.g., [010100]), with the result (e.g., [111101]) being retained in sensing circuitry 450 as bit-vector 483. The result of the OR operation (e.g., [111101]) is copied to the cells storing bit-vector 474-1. As such, as shown in FIG. 4E, bit-vectors 474-1 and 483 are [111101] after the third phase.
FIG. 4K and the pseudocode referenced by reference numbers 4.k-4.n corresponds to a fourth phase of the second iterations. At reference number 4.k, the data pattern stored as bit-vector 480 is read into the sensing circuitry 450 such that bit-vector 483 is [101001]. At reference number 4.l, an AND operation is performed on the bit-vector 483 (e.g., [101001]) and bit-vector 478 (e.g., [010100]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [000000]. At reference number 4.m, the result of the AND operation (e.g., [000000]), which is stored as bit-vector 483, is shifted one bit position to the left, such that bit-vector 483 is [000000]). At reference number 4.n, the result of the left shift operation (e.g., [000000]) is copied to the cells storing bit-vector 482. As such, as shown in FIG. 4F, bit-vectors 482 and 483 are [000000] after the fourth phase.
FIG. 4L and the pseudocode referenced by reference numbers 4.o-4.s corresponds to a fifth phase of the second iteration. At reference number 4.o, the data pattern stored as bit-vector 476 is read into the sensing circuitry 450 such that bit-vector 483 is [101000]. At reference number 4.p, an invert operation is performed on bit-vector 483 such that bit-vector 483 stores [010111](e.g., the inverse of its previous data pattern). At reference number 4.q, an AND operation is performed on the bit-vector 483 (e.g., [010111]) and bit-vector 474-1 (e.g., [111101]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [010101]. The result of the AND operation (e.g., [010101]), which is stored as bit-vector 483, is ORed with the Temp Row 2 bit-vector 482 (e.g., [000000]), with the result (e.g., [010101]) being retained in sensing circuitry 450 as bit-vector 483. The result of the OR operation (e.g., [010101]) is copied to the cells storing bit-vector 474-1. As such, as shown in FIG. 4L, bit-vectors 474-1 and 483 are [010101] after the fifth phase.
FIG. 4L shows the states of memory cells of array 430 after a second iteration of the “For” loop associated with reference number 4. After the second iteration of the “For” loop, the 1-bit from bit-vector 488-0 (e.g., [011] before the second iteration) is swapped with a 0-bit from bit-vector 488-1 (e.g., [001] before the second iteration) and the 1-bit from bit-vector 488-2 (e.g., [010] before the second iterations) is swapped with a 0-bit from bit-vector 488-3 (e.g., [100] before the second iteration). FIGS. 4M to 4Q show the state of memory cells of array 430 after a third iteration of the “For” loop associated with reference number 4.
FIGS. 4M-4Q correspond to a third iteration of the iterations phase (e.g., an initial execution of the “For” loop corresponding to the pseudocode referenced by 4.a to 4.s and for which the index n is 2). A first phase of the third iteration corresponds to the pseudocode referenced by reference numbers 4.a and 4.b and FIG. 4M, and is associated with storing the data pattern of the “Row n bit-vector” in the cells corresponding to the Temp Row 1 bit-vector 480. For instance, a copy of the data stored in a third row of cells comprising data to be swapped (e.g., cells coupled to access line 404-2) is stored in the cells corresponding to Temp Row 1 bit-vector 480. For this iteration (e.g., the third iteration), the index “n” is 2 (e.g., n=2 for the third iteration of the “For” loop). At reference number 4.a of the pseudocode (e.g., “readRow(Row(n))”), the data pattern corresponding to the “Row n bit-vector” is read into the sensing circuitry corresponding to bit-vector 483. Since n=2 for the third iteration of the “For” loop, the data pattern corresponding to the Row 2 bit-vector 474-2 (e.g., [000110]) is read into the sensing circuitry 450, such that bit-vector 483 is [000110], as shown in FIG. 4M. At reference number 4.b, the data pattern corresponding to bit-vector 483 is copied to the cells storing the Temp Row 1 bit-vector 480. As such, Temp Row 1 bit-vector 480 is [000110] as shown in FIG. 4M.
FIG. 4N and the pseudocode referenced by reference numbers 4.c-4.e corresponds to a second phase of the third iteration. At reference number 4.c, the data pattern stored as bit-vector 483 is shifted one bit-position to the right, such that bit-vector 483 is [000011], which is the previous bit-vector 483 (e.g., [000110]) shifted right one bit position. At reference number 4.d, an AND operation is performed on bit-vector 478 (e.g., [010100]) and bit-vector 483 (e.g., [000011]). ANDing” bit-vectors 478 and 483 (e.g., [010100] AND [000011]) results in [000000] being stored as bit-vector 483 (e.g., the result of the AND operation is stored in the sensing circuitry 450). As such, bit-vector 483 is [000000] as shown in FIG. 4N. At reference number 4.e, the data pattern corresponding to bit-vector 483 is copied to the cells storing the Temp Row 2 bit-vector 482. As such, Temp Row 2 bit-vector 482 is [000000] as shown in FIG. 4N.
FIG. 4O and the pseudocode referenced by reference numbers 4.f-4.j corresponds to a third phase of the third iteration. At reference number 4.f, the data pattern stored as bit-vector 478 is read into the sensing circuitry 450 such that bit-vector 483 is [010100]. At reference number 4.g, an invert operation is performed on bit-vector 483 such that bit-vector 483 stores [101011](e.g., the inverse of its previous data pattern). At reference number 4.h, an AND operation is performed on the bit-vector 483 (e.g., [101011]) and bit-vector 474-2 (e.g., [000110]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [000010]. The result of the AND operation (e.g., [000010]), which is stored as bit-vector 483, is ORed with the Temp Row 2 bit-vector 482 (e.g., [000000]), with the result (e.g., [000010]) being retained in sensing circuitry 450 as bit-vector 483. The result of the OR operation (e.g., [000010]) is copied to the cells storing bit-vector 474-2. As such, as shown in FIG. 4O, bit-vectors 474-2 and 483 are [000010] after the third phase.
FIG. 4P and the pseudocode referenced by reference numbers 4.k-4.n corresponds to a fourth phase of the third iteration. At reference number 4.k, the data pattern stored as bit-vector 480 is read into the sensing circuitry 450 such that bit-vector 483 is [000110]. At reference number 4.l, an AND operation is performed on the bit-vector 483 (e.g., [0000110]) and bit-vector 478 (e.g., [010100]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [000100]. At reference number 4.m, the result of the AND operation (e.g., [000100]), which is stored as bit-vector 483, is shifted one bit position to the left, such that bit-vector 483 is [001000]). At reference number 4.n, the result of the left shift operation (e.g., [001000]) is copied to the cells storing bit-vector 482. As such, as shown in FIG. 4F, bit-vectors 482 and 483 are [001000] after the fourth phase.
FIG. 4Q and the pseudocode referenced by reference numbers 4.o-4.s corresponds to a fifth phase of the third iteration. At reference number 4.o, the data pattern stored as bit-vector 476 is read into the sensing circuitry 450 such that bit-vector 483 is [101000]. At reference number 4.p, an invert operation is performed on bit-vector 483 such that bit-vector 483 stores [010111](e.g., the inverse of its previous data pattern). At reference number 4.q, an AND operation is performed on the bit-vector 483 (e.g., [010111]) and bit-vector 474-2 (e.g., [001010]), the result being retained in the sensing circuitry 450 such that bit-vector 483 is [000010]. The result of the AND operation (e.g., [000010]), which is stored as bit-vector 483, is ORed with the Temp Row 2 bit-vector 482 (e.g., [001000]), with the result (e.g., [000110]) being retained in sensing circuitry 450 as bit-vector 483. The result of the OR operation (e.g., [000110]) is copied to the cells storing bit-vector 474-2. As such, as shown in FIG. 4G, bit-vectors 474-2 and 483 are [000110] after the fifth phase.
FIG. 4Q shows the states of memory cells of array 430 after a third iteration of the “For” loop associated with reference number 4. After the third iteration of the “For” loop, the 0-bit from bit-vector 488-0 (e.g., [011] before the first iteration) is swapped with a 0-bit from bit-vector 488-1 (e.g., [001] before the first iteration) and the 0-bit from bit-vector 488-2 (e.g., a bit-vector [010] before the first iteration) is swapped with a 1-bit from bit-vector 488-3 (e.g., [100] before the first iteration).
More or less iterations of operations can be performed than those shown herein in examples with elements that have an element width that is different than an element width of three. For example, if Elements 488 had an element width of four instead of three, then four iterations of operations can be performed.
Furthermore, the swap operation can swap more than four elements (e.g., swap bit-vector 488-0 with bit-vector 488-1 and bit-vector 488-2 with bit-vector 488-3). For example, the swap operation can swap six elements, eight elements, ten elements, etc.
Embodiments however, are not limited to the order of the sequence of instructions in the pseudocode in this example. For example, a number of operations reference in reference numbers 4.c to 4.j can be performed before a number of operations reference in reference numbers 4.k to 4.q are performed.
The functionality of the sensing circuitry 250 of FIG. 2A is described below and summarized in Table 1 below with respect to performing logical operations and initially storing a result in the sense amplifier 206. Initially storing the result of a particular logical operation in the primary latch of sense amplifier 206 can provide improved versatility as compared to previous approaches in which the result may initially reside in a secondary latch (e.g., accumulator) of a compute component 231, and then be subsequently transferred to the sense amplifier 206, for instance.











TABLE 1







Operation
Accumulator
Sense Amp









AND
Unchanged
Result



OR
Unchanged
Result



NOT
Unchanged
Result



SHIFT
Unchanged
Shifted Data










Initially storing the result of a particular operation in the sense amplifier 206 (e.g., without having to perform an additional operation to move the result from the compute component 231 (e.g., accumulator) to the sense amplifier 206) is advantageous because, for instance, the result can be written to a row (of the array of memory cells) or back into the accumulator without performing a precharge cycle (e.g., on the complementary data lines 205-1 (D) and/or 205-2 (D_)).
FIG. 5 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure. FIG. 5 illustrates a timing diagram associated with initiating an AND logical operation on a first operand and a second operand. In this example, the first operand is stored in a memory cell coupled to a first access line (e.g., ROW X) and the second operand is stored in a memory cell coupled to a second access line (e.g., ROW Y). Although the example refers to performing an AND on data stored in cells corresponding to one particular column, embodiments are not so limited. For instance, an entire row of data values can be ANDed, in parallel, with a different row of data values. For example, if an array comprises 2,048 columns, then 2,048 AND operations could be performed in parallel.
FIG. 5 illustrates a number of control signals associated with operating sensing circuitry (e.g., 250) to perform the AND logical operation. “EQ” corresponds to an equilibrate signal applied to the sense amp 206, “ROW X” corresponds to an activation signal applied to access line 204-X, “ROW Y” corresponds to an activation signal applied to access line 204-Y, “Act” and “RnIF” correspond to a respective active positive and negative control signal applied to the sense amp 206, “LOAD” corresponds to a load control signal (e.g., LOAD/PASSD and LOAD/PASSDb shown in FIG. 2A), and “AND” corresponds to the AND control signal shown in FIG. 2A. FIG. 5 also illustrates the waveform diagrams showing the signals (e.g., voltage signals) on the digit lines D and D_ corresponding to sense amp 206 and on the nodes S1 and S2 corresponding to the compute component 231 (e.g., Accum) during an AND logical operation for the various data value combinations of the Row X and Row Y data values (e.g., diagrams correspond to respective data value combinations 00, 10, 01, 11). The particular timing diagram waveforms are discussed below with respect to the pseudo code associated with an AND operation of the circuit shown in FIG. 2A.
An example of pseudo code associated with loading (e.g., copying) a first data value stored in a cell coupled to row 204-X into the accumulator can be summarized as follows:












Copy Row X into the Accumulator:









Deactivate EQ;



Open Row X;



Fire Sense Amps (after which Row X data resides in the







sense amps);









Activate LOAD (sense amplifier data (Row X) is transferred







to nodes S1 and S2 of the Accumulator and resides there dynamically);









Deactivate LOAD;



Close Row X;



Precharge;










In the pseudo code above, “Deactivate EQ” indicates that an equilibration signal (EQ signal shown in FIG. 5) corresponding to the sense amplifier 206 is disabled at t1 as shown in FIG. 5 (e.g., such that the complementary data lines (e.g., 205-1 (D) and 205-2 (D_) are no longer shorted to VDD/2). After equilibration is disabled, a selected row (e.g., ROW X) is enabled (e.g., selected, opened such as by activating a signal to select a particular row) as indicated by “Open Row X” in the pseudo code and shown at t2 for signal Row X in FIG. 5. When the voltage signal applied to ROW X reaches the threshold voltage (Vt) of the access transistor (e.g., 202-2) corresponding to the selected cell, the access transistor turns on and couples the data line (e.g., 205-2 (D_)) to the selected cell (e.g., to capacitor 203-2) which creates a differential voltage signal between the data lines.
After Row X is enabled (e.g., activated), in the pseudo code above, “Fire Sense Amps” indicates that the sense amplifier 206 is enabled to set the primary latch and subsequently disabled. For example, as shown at t3 in FIG. 5, the ACT positive control signal (e.g., 265 shown in FIG. 2B) goes high and the RnIF negative control signal (e.g., 228 shown in FIG. 2B) goes low, which amplifies the differential signal between 205-1 (D) and D_ 205-2, resulting in a voltage (e.g., VDD) corresponding to a logic 1 or a voltage (e.g., GND) corresponding to a logic 0 being on data line 205-1 (D) (and the voltage corresponding to the other logic state being on complementary data line 205-2 (D_)). The sensed data value is stored in the primary latch of sense amplifier 206. The primary energy consumption occurs in charging the data lines (e.g., 205-1 (D) or 205-2 (D_)) from the equilibration voltage VDD/2 to the rail voltage VDD.
The four sets of possible sense amplifier and accumulator signals illustrated in FIG. 5 (e.g., one for each combination of Row X and Row Y data values) shows the behavior of signals on data lines D and D_. The Row X data value is stored in the primary latch of the sense amp. It should be noted that FIG. 2A shows that the memory cell including storage element 203-2 and access transistor 202-2, corresponding to Row X, is coupled to the complementary data line D_, while the memory cell including storage element 203-1 and access transistor 202-1, corresponding to Row Y, is coupled to data line D. However, as can be seen in FIG. 2A, the charge stored in the memory cell comprising access transistor 202-2 (corresponding to Row X) corresponding to a “0” data value causes the voltage on data line D_ (to which access transistor 202-2 is coupled) to go high and the charge stored in the memory cell comprising access transistor 202-2 corresponding to a “1” data value causes the voltage on data line D_ to go low, which is opposite correspondence between data states and charge stored in the memory cell comprising access transistor 202-1, corresponding to Row Y, that is coupled to data line D. These differences in storing charge in memory cells coupled to different data lines is appropriately accounted for when writing data values to the respective memory cells.
After firing the sense amps, in the pseudo code above, “Activate LOAD” indicates that the LOAD control signal goes high as shown at t4 in FIG. 5, causing load/pass transistors 218-1 and 218-2 to conduct. In this manner, activating the LOAD control signal enables the secondary latch in the accumulator of the compute component 231. The sensed data value stored in the sense amplifier 206 is transferred (e.g., copied) to the secondary latch. As shown for each of the four sets of possible sense amplifier and accumulator signals illustrated in FIG. 5, the behavior at inputs of the secondary latch of the accumulator indicates the secondary latch is loaded with the Row X data value. As shown in FIG. 5, the secondary latch of the accumulator may flip (e.g., see accumulator signals for Row X=“0” and Row Y=“0” and for Row X=“1” and Row Y=“0”), or not flip (e.g., see accumulator signals for Row X=“0” and Row Y=“1” and for Row X=“1” and Row Y=“1”), depending on the data value previously stored in the dynamic latch.
After setting the secondary latch from the data values stored in the sense amplifier (and present on the data lines 205-1 (D) and 205-2 (D_), in the pseudo code above, “Deactivate LOAD” indicates that the LOAD control signal goes back low as shown at t5 in FIG. 5 to cause the load/pass transistors 218-1 and 218-2 to stop conducting and thereby isolate the dynamic latch from the complementary data lines. However, the data value remains dynamically stored in secondary latch of the accumulator.
After storing the data value on the secondary latch, the selected row (e.g., ROW X) is disabled (e.g., deselected, closed such as by deactivating a select signal for a particular row) as indicated by “Close Row X” and indicated at t6 in FIG. 5, which can be accomplished by the access transistor turning off to decouple the selected cell from the corresponding data line. Once the selected row is closed and the memory cell is isolated from the data lines, the data lines can be precharged as indicated by the “Precharge” in the pseudo code above. A precharge of the data lines can be accomplished by an equilibrate operation, as indicated in FIG. 5 by the EQ signal going high at t7. As shown in each of the four sets of possible sense amplifier and accumulator signals illustrated in FIG. 5 at t7, the equilibrate operation causes the voltage on data lines D and D_ to each return to VDD/2. Equilibration can occur, for instance, prior to a memory cell sensing operation or the logical operations (described below).
A subsequent operation phase associated with performing the AND or the OR operation on the first data value (now stored in the sense amplifier 206 and the secondary latch of the compute component 231) and the second data value (stored in a memory cell 202-1 coupled to Row Y 204-Y) can include performing particular steps which depend on the whether an AND or an OR is to be performed. Examples of pseudo code associated with “ANDing” and “ORing” the data value residing in the accumulator (e.g., the first data value stored in the memory cell 202-2 coupled to Row X 204-X) and the second data value (e.g., the data value stored in the memory cell 202-1 coupled to Row Y 204-Y) are summarized below. Example pseudo code associated with “ANDing” the data values can include:












Deactivate EQ;


Open Row Y;


Fire Sense Amps (after which Row Y data resides in the sense amps);


Close Row Y;









The result of the logic operation, in the next operation, will be







placed on the sense amp, which will overwrite any row that is active;









Even when Row Y is closed, the sense amplifier still contains







the Row Y data value;


Activate AND;









This results in the sense amplifier being written to the value







of the function (e.g., Row X AND Row Y);









If the accumulator contains a “0” (i.e., a voltage







corresponding to a “0” on node S2 and a voltage corresponding to a “1”


on node S1), the sense amplifier data is written to a “0”;









If the accumulator contains a “1” (i.e., a voltage







corresponding to a “1” on node S2 and a voltage corresponding to a “0”


on node S1), the sense amplifier data remains unchanged (Row Y data);









This operation leaves the data in the accumulator unchanged;







Deactivate AND;


Precharge;









In the pseudo code above, “Deactivate EQ” indicates that an equilibration signal corresponding to the sense amplifier 206 is disabled (e.g., such that the complementary data lines 205-1 (D) and 205-2 (D_) are no longer shorted to VDD/2), which is illustrated in FIG. 5 at t8. After equilibration is disabled, a selected row (e.g., ROW Y) is enabled as indicated in the pseudo code above by “Open Row Y” and shown in FIG. 5 at t9. When the voltage signal applied to ROW Y reaches the threshold voltage (Vt) of the access transistor (e.g., 202-1) corresponding to the selected cell, the access transistor turns on and couples the data line (e.g., D_ 205-1) to the selected cell (e.g., to capacitor 203-1) which creates a differential voltage signal between the data lines.
After Row Y is enabled, in the pseudo code above, “Fire Sense Amps” indicates that the sense amplifier 206 is enabled to amplify the differential signal between 205-1 (D) and 205-2 (D_), resulting in a voltage (e.g., VDD) corresponding to a logic 1 or a voltage (e.g., GND) corresponding to a logic 0 being on data line 205-1 (D) (and the voltage corresponding to the other logic state being on complementary data line 205-2 (D_)). As shown at t10 in FIG. 5, the ACT positive control signal (e.g., 265 shown in FIG. 2B) goes high and the RnIF negative control signal (e.g., 228 shown in FIG. 2B) goes low to fire the sense amps. The sensed data value from memory cell 202-1 is stored in the primary latch of sense amplifier 206, as previously described. The secondary latch still corresponds to the data value from memory cell 202-2 since the dynamic latch is unchanged.
After the second data value sensed from the memory cell 202-1 coupled to Row Y is stored in the primary latch of sense amplifier 206, in the pseudo code above, “Close Row Y” indicates that the selected row (e.g., ROW Y) can be disabled if it is not desired to store the result of the AND logical operation back in the memory cell corresponding to Row Y. However, FIG. 5 shows that Row Y is left enabled such that the result of the logical operation can be stored back in the memory cell corresponding to Row Y. Isolating the memory cell corresponding to Row Y can be accomplished by the access transistor turning off to decouple the selected cell 202-1 from the data line 205-1 (D). After the selected Row Y is configured (e.g., to isolate the memory cell or not isolate the memory cell), “Activate AND” in the pseudo code above indicates that the AND control signal goes high as shown in FIG. 5 at t11, causing pull down transistor 207-1 to conduct. In this manner, activating the AND control signal causes the value of the function (e.g., Row X AND Row Y) to be written to the sense amp.
With the first data value (e.g., Row X) stored in the dynamic latch of the accumulator 231 and the second data value (e.g., Row Y) stored in the sense amplifier 206, if the dynamic latch of the compute component 231 contains a “0” (i.e., a voltage corresponding to a “0” on node S2 and a voltage corresponding to a “1” on node S1), the sense amplifier data is written to a “0” (regardless of the data value previously stored in the sense amp) since the voltage corresponding to a “1” on node S1 causes transistor 209-1 to conduct thereby coupling the sense amplifier 206 to ground through transistor 209-1, pull down transistor 207-1 and data line 205-1 (D). When either data value of an AND operation is “0,” the result is a “0.” Here, when the second data value (in the dynamic latch) is a “0,” the result of the AND operation is a “0” regardless of the state of the first data value, and so the configuration of the sensing circuitry causes the “0” result to be written and initially stored in the sense amplifier 206. This operation leaves the data value in the accumulator unchanged (e.g., from Row X).
If the secondary latch of the accumulator contains a “1” (e.g., from Row X), then the result of the AND operation depends on the data value stored in the sense amplifier 206 (e.g., from Row Y). The result of the AND operation should be a “1” if the data value stored in the sense amplifier 206 (e.g., from Row Y) is also a “1,” but the result of the AND operation should be a “0” if the data value stored in the sense amplifier 206 (e.g., from Row Y) is also a “0.” The sensing circuitry 250 is configured such that if the dynamic latch of the accumulator contains a “1” (i.e., a voltage corresponding to a “1” on node S2 and a voltage corresponding to a “0” on node S1), transistor 209-1 does not conduct, the sense amplifier is not coupled to ground (as described above), and the data value previously stored in the sense amplifier 206 remains unchanged (e.g., Row Y data value so the AND operation result is a “1” if the Row Y data value is a “1” and the AND operation result is a “0” if the Row Y data value is a “0”). This operation leaves the data value in the accumulator unchanged (e.g., from Row X).
After the result of the AND operation is initially stored in the sense amplifier 206, “Deactivate AND” in the pseudo code above indicates that the AND control signal goes low as shown at t12 in FIG. 5, causing pull down transistor 207-1 to stop conducting to isolate the sense amplifier 206 (and data line 205-1 (D)) from ground. If not previously done, Row Y can be closed (as shown at t13 in FIG. 5) and the sense amplifier can be disabled (as shown at t14 in FIG. 5 by the ACT positive control signal going low and the RnIF negative control signal goes high). With the data lines isolated, “Precharge” in the pseudo code above can cause a precharge of the data lines by an equilibrate operation, as described previously (e.g., commencing at t14 shown in FIG. 5).
FIG. 5 shows, in the alternative, the behavior of voltage signals on the data lines (e.g., 205-1 (D) and 205-2 (D_) shown in FIG. 2A) coupled to the sense amplifier (e.g., 206 shown in FIG. 2A) and the behavior of voltage signals on nodes S1 and S2 of the secondary latch of the compute component (e.g., 231 shown in FIG. 2A) for an AND logical operation involving each of the possible combination of operands (e.g., Row X/Row Y data values 00, 10, 01, and 11).
Although the timing diagrams illustrated in FIG. 5 and the pseudo code described above indicate initiating the AND logical operation after starting to load the second operand (e.g., Row Y data value) into the sense amplifier, the circuit shown in FIG. 2A can be successfully operated by initiating the AND logical operation before starting to load the second operand (e.g., Row Y data value) into the sense amplifier.
FIG. 6 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure. FIG. 6 illustrates a timing diagram associated with initiating an OR logical operation after starting to load the second operand (e.g., Row Y data value) into the sense amplifier. FIG. 6 illustrates the sense amplifier and accumulator signals for various combinations of first and second operand data values. The particular timing diagram signals are discussed below with respect to the pseudo code associated with an AND logical operation of the circuit shown in FIG. 2A.
A subsequent operation phase can alternately be associated with performing the OR operation on the first data value (now stored in the sense amplifier 206 and the secondary latch of the compute component 231) and the second data value (stored in a memory cell 202-1 coupled to Row Y 204-Y). The operations to load the Row X data into the sense amplifier and accumulator that were previously described with respect to times t1-t7 shown in FIG. 5 are not repeated with respect to FIG. 6. Example pseudo code associated with “ORing” the data values can include:












Deactivate EQ;


Open Row Y;


Fire Sense Amps (after which Row Y data resides in the sense amps);


Close Row Y;









When Row Y is closed, the sense amplifier still contains the Row Y



data value;







Activate OR;









This results in the sense amplifier being written to the value of









the function (e.g., Row X OR Row Y), which may overwrite the data



value from Row Y previously stored in the sense amplifier as



follows:









If the accumulator contains a “0” (i.e., a voltage corresponding









to a “0” on node S2 and a voltage corresponding to a “1” on node



S1), the sense amplifier data remains unchanged (Row Y data);









If the accumulator contains a “1” (i.e., a voltage corresponding









to a “1” on node S2 and a voltage corresponding to a “0” on node



S1), the sense amplifier data is written to a “1”;









This operation leaves the data in the accumulator unchanged;









Deactivate OR;



Precharge;










The “Deactivate EQ” (shown at t8 in FIG. 6), “Open Row Y” (shown at t9 in FIG. 6), “Fire Sense Amps” (shown at t10 in FIG. 6), and “Close Row Y” (shown at t13 in FIG. 6, and which may occur prior to initiating the particular logical function control signal), shown in the pseudo code above indicate the same functionality as previously described with respect to the AND operation pseudo code. Once the configuration of selected Row Y is appropriately configured (e.g., enabled if logical operation result is to be stored in memory cell corresponding to Row Y or closed to isolate memory cell if result if logical operation result is not to be stored in memory cell corresponding to Row Y), “Activate OR” in the pseudo code above indicates that the OR control signal goes high as shown at t11 in FIG. 6, which causes pull down transistor 207-2 to conduct. In this manner, activating the OR control signal causes the value of the function (e.g., Row X OR Row Y) to be written to the sense amp.
With the first data value (e.g., Row X) stored in the secondary latch of the compute component 231 and the second data value (e.g., Row Y) stored in the sense amplifier 206, if the dynamic latch of the accumulator contains a “0” (i.e., a voltage corresponding to a “0” on node S2 and a voltage corresponding to a “1” on node S1), then the result of the OR operation depends on the data value stored in the sense amplifier 206 (e.g., from Row Y). The result of the OR operation should be a “1” if the data value stored in the sense amplifier 206 (e.g., from Row Y) is a “1,” but the result of the OR operation should be a “0” if the data value stored in the sense amplifier 206 (e.g., from Row Y) is also a “0.” The sensing circuitry 250 is configured such that if the dynamic latch of the accumulator contains a “0,” with the voltage corresponding to a “0” on node S2, transistor 209-2 is off and does not conduct (and pull down transistor 207-1 is also off since the AND control signal is not asserted) so the sense amplifier 206 is not coupled to ground (either side), and the data value previously stored in the sense amplifier 206 remains unchanged (e.g., Row Y data value such that the OR operation result is a “1” if the Row Y data value is a “1” and the OR operation result is a “0” if the Row Y data value is a “0”).
If the dynamic latch of the accumulator contains a “1” (i.e., a voltage corresponding to a “1” on node S2 and a voltage corresponding to a “0” on node S1), transistor 209-2 does conduct (as does pull down transistor 207-2 since the OR control signal is asserted), and the sense amplifier 206 input coupled to data line 205-2 (D_) is coupled to ground since the voltage corresponding to a “1” on node S2 causes transistor 209-2 to conduct along with pull down transistor 207-2 (which also conducts since the OR control signal is asserted). In this manner, a “1” is initially stored in the sense amplifier 206 as a result of the OR operation when the secondary latch of the accumulator contains a “1” regardless of the data value previously stored in the sense amp. This operation leaves the data in the accumulator unchanged. FIG. 6 shows, in the alternative, the behavior of voltage signals on the data lines (e.g., 205-1 (D) and 205-2 (D_) shown in FIG. 2A) coupled to the sense amplifier (e.g., 206 shown in FIG. 2A) and the behavior of voltage signals on nodes S1 and S2 of the secondary latch of the compute component 231 for an OR logical operation involving each of the possible combination of operands (e.g., Row X/Row Y data values 00, 10, 01, and 11).
After the result of the OR operation is initially stored in the sense amplifier 206, “Deactivate OR” in the pseudo code above indicates that the OR control signal goes low as shown at t12 in FIG. 6, causing pull down transistor 207-2 to stop conducting to isolate the sense amplifier 206 (and data line D 205-2) from ground. If not previously done, Row Y can be closed (as shown at t13 in FIG. 6) and the sense amplifier can be disabled (as shown at t14 in FIG. 6 by the ACT positive control signal going low and the RnIF negative control signal going high). With the data lines isolated, “Precharge” in the pseudo code above can cause a precharge of the data lines by an equilibrate operation, as described previously and shown at t14 in FIG. 6.
The sensing circuitry 250 illustrated in FIG. 2A can provide additional logical operations flexibility as follows. By substituting operation of the ANDinv control signal for operation of the AND control signal, and/or substituting operation of the ORinv control signal for operation of the OR control signal in the AND and OR operations described above, the logical operations can be changed from {Row X AND Row Y} to { ̃Row X AND Row Y}(where “ ̃Row X” indicates an opposite of the Row X data value, e.g., NOT Row X) and can be changed from {Row X OR Row Y} to { ̃Row X OR Row Y}. For example, during an AND operation involving the inverted data values, the ANDinv control signal can be asserted instead of the AND control signal, and during an OR operation involving the inverted data values, the ORInv control signal can be asserted instead of the OR control signal. Activating the ORinv control signal causes transistor 214-1 to conduct and activating the ANDinv control signal causes transistor 214-2 to conduct. In each case, asserting the appropriate inverted control signal can flip the sense amplifier and cause the result initially stored in the sense amplifier 206 to be that of the AND operation using inverted Row X and true Row Y data values or that of the OR operation using the inverted Row X and true Row Y data values. A true or compliment version of one data value can be used in the accumulator to perform the logical operation (e.g., AND, OR), for example, by loading a data value to be inverted first and a data value that is not to be inverted second.
In a similar approach to that described above with respect to inverting the data values for the AND and OR operations described above, the sensing circuitry shown in FIG. 2A can perform a NOT (e.g., invert) operation by putting the non-inverted data value into the dynamic latch of the accumulator and using that data to invert the data value in the sense amplifier 206. As previously mentioned, activating the ORinv control signal causes transistor 214-1 to conduct and activating the ANDinv control signal causes transistor 214-2 to conduct. The ORinv and/or ANDinv control signals are used in implementing the NOT function, as described further below:












Copy Row X into the Accumulator;









Deactivate EQ;



Open Row X;



Fire Sense Amps (after which Row X data resides in the sense amps);



Activate LOAD (sense amplifier data (Row X) is transferred to nodes







S1 and S2 of the Accumulator and resides there dynamically;









Deactivate LOAD;



Activate ANDinv and ORinv (which puts the compliment data value







on the data lines);









This results in the data value in the sense amplifier being









inverted (e.g., the sense amplifier latch is flipped);









This operation leaves the data in the accumulator unchanged;









Deactivate ANDinv and ORinv;



Close Row X;



Precharge;










The “Deactivate EQ,” “Open Row X,” “Fire Sense Amps,” “Activate LOAD,” and “Deactivate LOAD” shown in the pseudo code above indicate the same functionality as the same operations in the pseudo code for the “Copy Row X into the Accumulator” initial operation phase described above prior to pseudo code for the AND operation and OR operation. However, rather than closing the Row X and Precharging after the Row X data is loaded into the sense amplifier 206 and copied into the dynamic latch, a complement version of the data value in the dynamic latch of the accumulator can be placed on the data line and thus transferred to the sense amplifier 206 by enabling (e.g., causing transistor to conduct) and disabling the invert transistors (e.g., ANDinv and ORinv). This results in the sense amplifier 206 being flipped from the true data value that was previously stored in the sense amplifier to a complement data value (e.g., inverted data value) stored in the sense amp. For instance, a true or complement version of the data value in the accumulator can be transferred to the sense amplifier by activating and deactivating ANDinv and ORinv. This operation leaves the data in the accumulator unchanged.
Because the sensing circuitry 250 shown in FIG. 2A initially stores the result of the AND, OR, and NOT logical operations in the sense amplifier 206 (e.g., on the sense amplifier nodes), these logical operation results can be communicated easily and quickly to any enabled row, any row activated after the logical operation is complete, and/or into the secondary latch of the compute component 231. The sense amplifier 206 and sequencing for the AND, OR, and/or NOT logical operations can also be interchanged by appropriate firing of the AND, OR, ANDinv, and/or ORinv control signals (and operation of corresponding transistors having a gate coupled to the particular control signal) before the sense amplifier 206 fires.
When performing logical operations in this manner, the sense amplifier 206 can be pre-seeded with a data value from the dynamic latch of the accumulator to reduce overall current utilized because the sense amps 206 are not at full rail voltages (e.g., supply voltage or ground/reference voltage) when accumulator function is copied to the sense amplifier 206. An operation sequence with a pre-seeded sense amplifier 206 either forces one of the data lines to the reference voltage (leaving the complementary data line at VDD/2, or leaves the complementary data lines unchanged. The sense amplifier 206 pulls the respective data lines to full rails when the sense amplifier 206 fires. Using this sequence of operations will overwrite data in an enabled row.
A SHIFT operation can be accomplished by multiplexing (“muxing”) two neighboring data line complementary pairs using a traditional DRAM isolation (ISO) scheme. According to embodiments of the present disclosure, the shift circuitry 223 can be used for shifting data values stored in memory cells coupled to a particular pair of complementary data lines to the sensing circuitry 250 (e.g., sense amplifier 206) corresponding to a different pair of complementary data lines (e.g., such as a sense amplifier 206 corresponding to a left or right adjacent pair of complementary data lines. As used herein, a sense amplifier 206 corresponds to the pair of complementary data lines to which the sense amplifier is coupled when isolation transistors 221-1 and 221-2 are conducting. The SHIFT operations (right or left) do not pre-copy the Row X data value into the accumulator. Operations to shift right Row X can be summarized as follows:












Deactivate Norm and Activate Shift;


Deactivate EQ;


Open Row X;


Fire Sense Amps (after which shifted Row X data resides in the sense


amps);


Activate Norm and Deactivate Shift;


Close Row X;


Precharge;









In the pseudo code above, “Deactivate Norm and Activate Shift” indicates that a NORM control signal goes low causing isolation transistors 221-1 and 221-2 of the shift circuitry 223 to not conduct (e.g., isolate the sense amplifier from the corresponding pair of complementary data lines). The SHIFT control signal goes high causing isolation transistors 221-3 and 221-4 to conduct, thereby coupling the sense amplifier 206 to the left adjacent pair of complementary data lines (e.g., on the memory array side of non-conducting isolation transistors 221-1 and 221-2 for the left adjacent pair of complementary data lines).
After the shift circuitry 223 is configured, the “Deactivate EQ,” “Open Row X,” and “Fire Sense Amps” shown in the pseudo code above indicate the same functionality as the same operations in the pseudo code for the “Copy Row X into the Accumulator” initial operation phase described above prior to pseudo code for the AND operation and OR operation. After these operations, the Row X data value for the memory cell coupled to the left adjacent pair of complementary data lines is shifted right and stored in the sense amplifier 206.
In the pseudo code above, “Activate Norm and Deactivate Shift” indicates that a NORM control signal goes high causing isolation transistors 221-1 and 221-2 of the shift circuitry 223 to conduct (e.g., coupling the sense amplifier to the corresponding pair of complementary data lines), and the SHIFT control signal goes low causing isolation transistors 221-3 and 221-4 to not conduct and isolating the sense amplifier 206 from the left adjacent pair of complementary data lines (e.g., on the memory array side of non-conducting isolation transistors 221-1 and 221-2 for the left adjacent pair of complementary data lines). Since Row X is still active, the Row X data value that has been shifted right is transferred to Row X of the corresponding pair of complementary data lines through isolation transistors 221-1 and 221-2.
After the Row X data values are shifted right to the corresponding pair of complementary data lines, the selected row (e.g., ROW X) is disabled as indicated by “Close Row X” in the pseudo code above, which can be accomplished by the access transistor turning off to decouple the selected cell from the corresponding data line. Once the selected row is closed and the memory cell is isolated from the data lines, the data lines can be precharged as indicated by the “Precharge” in the pseudo code above. A precharge of the data lines can be accomplished by an equilibrate operation, as described above. Operations to shift left Row X can be summarized as follows:












Activate Norm and Deactivate Shift;


Deactivate EQ;


Open Row X;


Fire Sense Amps (after which Row X data resides in the sense amps);


Deactivate Norm and Activate Shift;









Sense amplifier data (shifted left Row X) is transferred to Row X;







Close Row X;


Precharge;









In the pseudo code above, “Activate Norm and Deactivate Shift” indicates that a NORM control signal goes high causing isolation transistors 221-1 and 221-2 of the shift circuitry 223 to conduct, and the SHIFT control signal goes low causing isolation transistors 221-3 and 221-4 to not conduct. This configuration couples the sense amplifier 206 to a corresponding pair of complementary data lines and isolates the sense amplifier from the right adjacent pair of complementary data lines.
After the shift circuitry is configured, the “Deactivate EQ,” “Open Row X,” and “Fire Sense Amps” shown in the pseudo code above indicate the same functionality as the same operations in the pseudo code for the “Copy Row X into the Accumulator” initial operation phase described above prior to pseudo code for the AND operation and OR operation. After these operations, the Row X data value for the memory cell coupled to the pair of complementary data lines corresponding to the sense circuitry 250 is stored in the sense amplifier 206.
In the pseudo code above, “Deactivate Norm and Activate Shift” indicates that a NORM control signal goes low causing isolation transistors 221-1 and 221-2 of the shift circuitry 223 to not conduct (e.g., isolate the sense amplifier from the corresponding pair of complementary data lines), and the SHIFT control signal goes high causing isolation transistors 221-3 and 221-4 to conduct coupling the sense amplifier to the left adjacent pair of complementary data lines (e.g., on the memory array side of non-conducting isolation transistors 221-1 and 221-2 for the left adjacent pair of complementary data lines. Since Row X is still active, the Row X data value that has been shifted left is transferred to Row X of the left adjacent pair of complementary data lines.
After the Row X data values are shifted left to the left adjacent pair of complementary data lines, the selected row (e.g., ROW X) is disabled as indicated by “Close Row X,” which can be accomplished by the access transistor turning off to decouple the selected cell from the corresponding data line. Once the selected row is closed and the memory cell is isolated from the data lines, the data lines can be precharged as indicated by the “Precharge” in the pseudo code above. A precharge of the data lines can be accomplished by an equilibrate operation, as described above.
According to various embodiments, general computing can be enabled in a memory array core of a processor-in-memory (PIM) device such as a DRAM one transistor per memory cell (e.g., 1T1C) configuration at 6F^2 or 4F^2 memory cell sizes, for example. A potential advantage of the apparatuses and methods described herein may not be realized in terms of single instruction speed, but rather can be realized in the cumulative speed that can be achieved by an entire bank of data being computed in parallel without necessarily transferring data out of the memory array (e.g., DRAM) or firing a column decode. In other words, data transfer time can be reduced or eliminated. For example, apparatus of the present disclosure can perform ANDs or ORs simultaneously using data values in memory cells coupled to a data line (e.g., a column of 16K memory cells).
In previous approach sensing circuits where data is moved out for logical operation processing (e.g., using 32 or 64 bit registers), fewer operations can be performed in parallel compared to the apparatus of the present disclosure. In this manner, significantly higher throughput is effectively provided in contrast to conventional configurations involving a central processing unit (CPU) discrete from the memory such that data must be transferred therebetween. An apparatus and/or methods according to the present disclosure can also use less energy/area than configurations where the CPU is discrete from the memory. Furthermore, an apparatus and/or methods of the present disclosure can improve upon the smaller energy/area advantages since the in-memory-array logical operations save energy by eliminating certain data value transfers.
FIG. 7 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure. The functionality of the sensing circuitry 250 of FIG. 2A is described below with respect to performing logical operations and initially storing a result in the compute component 231 (e.g., secondary latch of the accumulator). The timing diagram shown in FIG. 7 illustrates signals (e.g., voltage signals) associated with performing a first operation phase of a logical operation (e.g., an R-input logical operation) using the sensing circuitry illustrated in FIG. 2A. The first operation phase described with respect to FIG. 7 can be a first operation phase of an AND, NAND, OR, or NOR operation, for instance. Performing the operation phase illustrated in FIG. 7 can involve consuming significantly less energy (e.g., about half) than previous processing approaches that may involve providing a full swing between voltage rails (e.g., between a supply and ground).
In the example illustrated in FIG. 7, the voltage rails corresponding to complementary logic values (e.g., “1” and “0”) are a supply voltage (VDD) and a reference voltage (e.g., ground (Gnd)). Prior to performing a logical operation, an equilibration can occur such that the complementary data lines D and D_ are shorted together at an equilibration voltage (VDD/2), as previously described.
The first operation phase of a logical operation described below involves loading a first operand of the logical operation into the accumulator. The time references (e.g., t1, etc.) shown in FIG. 7 do not necessarily represent a same absolute or relative time as similar time references in other timing diagrams.
t time t1, the equilibration signal 726 is deactivated, and then a selected row is enabled (e.g., the row corresponding to a memory cell whose data value is to be sensed and used as a first input). Signal 704-0 represents the voltage signal applied to the selected row (e.g., Row Y 204-Y shown in FIG. 2A). When row signal 704-0 reaches the threshold voltage (Vt) of the access transistor (e.g., 202-1 shown in FIG. 2A) corresponding to the selected cell, the access transistor turns on and couples the data line D to the selected memory cell (e.g., to the capacitor 203-1 shown in FIG. 2A if the cell is a 1T1C DRAM cell), which creates a differential voltage signal between the data lines D and D_ (e.g., as indicated by signals 705-1 and 705-2 on the data lines, respectively) between times t2 and t3. The voltage of the selected cell is represented by signal 703. Due to conservation of energy, creating the differential signal between data lines D and D_ (e.g., by coupling the cell to data line D) does not consume energy, since the energy associated with enabling/disabling the row signal 704-0 can be amortized over the plurality of memory cells coupled to the row.
At time t3, the sense amplifier (e.g., 206 shown in FIG. 2A) is activated (e.g., a positive control signal 765 (e.g., corresponding to ACT 265 shown in FIG. 2B) goes high and the negative control signal 728 (e.g., corresponding to RnIF 228 shown in FIG. 2B) goes low), which amplifies the differential signal between data lines D and D_, resulting in a voltage (e.g., VDD) corresponding to a logic “1” or a voltage (e.g., ground) corresponding to a logic “0” being on data line D (and the other voltage being on complementary data line D_), such that the sensed data value is stored in the primary latch of sense amplifier 206. The primary energy consumption occurs in charging the data line D (205-1) from the equilibration voltage VDD/2 to the rail voltage VDD. FIG. 7 shows, in example, the data line voltages 705-1 and 705-2 that correspond to a logic “1” being on data line D.
According to some embodiments, the primary latch of sense amplifier 206 can be coupled to the complementary data lines D and D_ through respective pass transistors (not shown in FIG. 2B but in a similar configuration as the manner in which latch 264 is coupled to the data lines D and D_ through load/pass transistors 218-1 and 218-2 shown in FIG. 2A). The Passd control signal 711 controls one pass transistor. The Passdb control signal controls the other pass transistor, and here the Passdb control signal can behave here the same as the Passd control signal.
At time t4, the pass transistors (if present) can be enabled (e.g., via respective Passd and Passdb control signals 711 applied to control lines coupled to the respective gates of the pass transistors going high). At time t5, the accumulator positive control signal 712-1 (e.g., Accumb) and the accumulator positive control signal 712-2 (e.g., Accum) are activated via respective control lines 212-1 and 212-2 shown in FIG. 2A. As described below, the accumulator control signals ACCUMB 712-1 and ACCUM 712-2 may remain activated for subsequent operation phases. As such, in this example, activating the control signals ACCUMB 712-1 and ACCUM 712-2 enables the secondary latch (e.g., accumulator) of compute component 231-6 shown in FIG. 2A. The sensed data value stored in sense amplifier 206 is transferred (e.g., copied) to the secondary latch, including the dynamic latch and latch 264.
At time t6, the Passd control signal 711 (and the Passdb control signal) goes low thereby turning off the pass transistors (if present). However, since the accumulator control signals ACCUMB 712-1 and ACCUM 712-2 remain activated, an accumulated result is stored (e.g., latched) in the secondary latches (e.g., accumulator). At time t7, the row signal 704-0 is deactivated, and the array sense amps are disabled at time t8 (e.g., sense amplifier control signals 728 and 765 are deactivated).
At time t9, the data lines D and D_ are equilibrated (e.g., equilibration signal 726 is activated), as illustrated by data line voltage signals 705-1 and 705-2 moving from their respective rail values to the equilibration voltage (VDD/2). The equilibration consumes little energy due to the law of conservation of energy. As described below in association with FIG. 2B, equilibration can involve shorting the complementary data lines D and D_ together at an equilibration voltage, which is VDD/2, in this example. Equilibration can occur, for instance, prior to a memory cell sensing operation.
FIGS. 8 and 9 respectively illustrate timing diagrams associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure. Timing diagrams shown in FIGS. 8 and 9 illustrate signals (e.g., voltage signals) associated with performing a number of intermediate operation phases of a logical operation (e.g., an R-input logical operation). For instance, timing diagram shown in FIG. 8 corresponds to a number of intermediate operation phases of an R-input NAND operation or an R-input AND operation, and timing diagram shown in FIG. 9 corresponds to a number of intermediate operation phases of an R-input NOR operation or an R-input OR operation. For example, performing an AND or NAND operation can include performing the operation phase shown in FIG. 8 one or more times subsequent to an initial operation phase such as that described with respect to FIG. 7. Similarly, performing an OR or NOR operation can include performing the operation phase shown and described with respect to FIG. 9 one or more times subsequent to an initial operation phase such as that described with respect to FIG. 7.
As shown in the timing diagrams illustrated in FIGS. 8 and 9, at time t1, equilibration is disabled (e.g., the equilibration signal 826/926 is deactivated), and then a selected row is enabled (e.g., the row corresponding to a memory cell whose data value is to be sensed and used as an input such as a second input, third input, etc.). Signal 804-1/904-1 represents the voltage signal applied to the selected row (e.g., Row Y 204-Y shown in FIG. 2A). When row signal 804-1 reaches the threshold voltage (Vt) of the access transistor (e.g., 202-1 shown in FIG. 2A) corresponding to the selected cell, the access transistor turns on and couples the data line D to the selected memory cell (e.g., to the capacitor 203-1 if the cell is a 1T1C DRAM cell), which creates a differential voltage signal between the data lines D and D_ (e.g., as indicated by signals 805-1/905-1 and 805-2/905-2, respectively) between times t2 and t3. The voltage of the selected cell is represented by signal 803/903. Due to conservation of energy, creating the differential signal between D and D_ (e.g., by coupling the cell to data line D) does not consume energy, since the energy associated with activating/deactivating the row signal 804-1/904-1 can be amortized over the plurality of memory cells coupled to the row.
At time t3, the sense amplifier (e.g., 206 shown in FIG. 2A) is enabled (e.g., a positive control signal 865/965 (e.g., corresponding to ACT 233 shown in FIG. 2B) goes high, and the negative control signal 828/928 (e.g., RnIF 228 shown in FIG. 2B) goes low), which amplifies the differential signal between D and D_, resulting in a voltage (e.g., VDD) corresponding to a logic 1 or a voltage (e.g., ground) corresponding to a logic 0 being on data line D (and the other voltage being on complementary data line D_), such that the sensed data value is stored in the primary latch of sense amplifier 206. The primary energy consumption occurs in charging the data line D (205-1) from the equilibration voltage VDD/2 to the rail voltage VDD.
As shown in timing diagrams illustrated in FIGS. 8 and 9, at time t4 (e.g., after the selected cell is sensed), only one of control signals 811-1 (Passd) shown in FIG. 8 and 911-2 (Passdb) shown in FIG. 9 is activated (e.g., only one of pass transistors (if present) is enabled), depending on the particular logic operation. For example, since the timing diagram illustrated in FIG. 8 corresponds to an intermediate phase of a NAND or AND operation, control signal 811-1 (Passd) is activated at time t4 to turn on the pass transistor coupling the primary latch to data line D and the Passdb control signal remains deactivated leaving the pass transistor coupling the primary latch to data line D_ turned off. Conversely, since the timing diagram illustrated in FIG. 9 corresponds to an intermediate phase of a NOR or OR operation, control signal 911-2 (Passdb) is activated at time t4 to turn on the pass transistor coupling the primary latch to data line D_ and control signal Passd remains deactivated leaving the pass transistor coupling the primary latch to data line D turned off. Recall from above that the accumulator control signals 712-1 (Accumb) and 712-2 (Accum) were activated during the initial operation phase described with respect to FIG. 7, and they remain activated during the intermediate operation phase(s).
Since the accumulator was previously enabled, activating only Passd (811-1 as shown in FIG. 8) results in accumulating the data value corresponding to the voltage signal 805-1 shown in FIG. 8 corresponding to data line D. Similarly, activating only Passdb (911-2 as shown in FIG. 9) results in accumulating the data value corresponding to the voltage signal 905-2 corresponding to data line D_. For instance, in an example AND/NAND operation shown in the timing diagram illustrated in FIG. 8 in which only Passd (811-1) is activated, if the data value stored in the second selected memory cell is a logic “0,” then the accumulated value associated with the secondary latch is asserted low such that the secondary latch stores logic “0.” If the data value stored in the second selected memory cell is not a logic “0,” then the secondary latch retains its stored first selected memory cell data value (e.g., a logic “1” or a logic “0”). As such, in this AND/NAND operation example, the secondary latch is serving as a zeroes (Os) accumulator.
Similarly, in an example OR/NOR operation shown in the timing diagram illustrated in FIG. 9 in which only Passdb 911-2 is activated, if the data value stored in the second selected memory cell is a logic “1,” then the accumulated value associated with the secondary latch is asserted high such that the secondary latch stores logic “1.” If the data value stored in the second selected memory cell is not a logic “1,” then the secondary latch retains its stored first selected memory cell data value (e.g., a logic “1” or a logic “0”). As such, in this OR/NOR operation example, the secondary latch is effectively serving as a ones (is) accumulator since voltage signal 905-2 on D_ is setting the true data value of the accumulator.
At the conclusion of an intermediate operation phase such as that shown in FIG. 8 or 9, the Passd signal 811-1 (e.g., for AND/NAND) or the Passdb signal 911-2 (e.g., for OR/NOR) is deactivated (e.g., at time t5), the selected row is disabled (e.g., at time t6), the sense amplifier is disabled (e.g., at time t7), and equilibration occurs (e.g., at time t8). An intermediate operation phase such as that illustrated in FIG. 8 or 9 can be repeated in order to accumulate results from a number of additional rows. As an example, the sequence of timing diagram illustrated in FIGS. 8 and/or 9 can be performed a subsequent (e.g., second) time for a third memory cell, a subsequent (e.g., third) time for a fourth memory cell, etc. For instance, for a 10-input NOR operation, the intermediate phase shown in FIG. 9 can occur 9 times to provide 9 inputs of the 10-input logical operation, with the tenth input being determined during the initial operation phase (e.g., as described with respect to FIG. 7).
FIG. 10 illustrates a timing diagram associated with performing a number of logical operations using sensing circuitry in accordance with a number of embodiments of the present disclosure. The timing diagram illustrated in FIG. 10 shows signals (e.g., voltage signals) associated with performing a last operation phase of a logical operation (e.g., an R-input logical operation). For instance, the timing diagram illustrated in FIG. 10 corresponds to a last operation phase of an R-input AND operation or an R-input OR operation.
For example, performing a last operation phase of an R-input can include performing the operation phase shown in FIG. 10 subsequent to a number of iterations of the intermediate operation phase(s) described in association with FIGS. 8 and/or 9. Table 2 shown below indicates the Figures corresponding to the sequence of operation phases associated with performing a number of R-input logical operations in accordance with a number of embodiments described herein.











TABLE 2





Operation
FIG. 7
FIG. 8
FIG. 9
FIG. 10







AND
First phase
R-1

Last phase




iterations


NAND
First phase
R-1




iterations


OR
First phase

R-1
Last phase





iterations


NOR
First phase

R-1





iterations









A NAND operation can be implemented, for example, by storing the result of the R−1 iterations for an AND operation in the sense amplifier, then inverting the sense amplifier before conducting the last operation phase to store the result (described below). A NOR operation can be implemented, for example, by storing the result of the R−1 iterations for an OR operation in the sense amplifier, then inverting the sense amplifier before conducting the last operation phase to store the result (described below).
The last operation phase illustrated in the timing diagram of FIG. 10 is described in association with storing a result of an R-input logical operation to a row of the array (e.g., array 230 shown in FIG. 2A). However, as described above, in a number of embodiments, the result can be stored to a suitable location other than back to the array (e.g., to an external register associated with a controller and/or host processor, to a memory array of a different memory device, etc., via I/O lines).
As shown in timing diagram illustrated in FIG. 10, at time t1, equilibration is disabled (e.g., the equilibration signal 1026 is deactivated) such that data lines D and D_ are floating. At time t2, the Passd control signal 1011 (and Passdb signal) is activated for an AND or OR operation.
Activating the Passd control signal 1011 (and Passdb signal) (e.g., in association with an AND or OR operation) transfers the accumulated output stored in the secondary latch of compute component 231-6 shown in FIG. 2A to the primary latch of sense amplifier 206. For instance, for an AND operation, if any of the memory cells sensed in the prior operation phases (e.g., the first operation phase illustrated in FIG. 7 and one or more iterations of the intermediate operation phase illustrated in FIG. 8) stored a logic “0” (e.g., if any of the R-inputs of the AND operation were a logic “0”), then the data line D_ will carry a voltage corresponding to logic “1” (e.g., VDD) and data line D will carry a voltage corresponding to logic “0” (e.g., ground). For this AND operation example, if all of the memory cells sensed in the prior operation phases stored a logic “1” (e.g., all of the R-inputs of the AND operation were logic “1”), then the data line D_ will carry a voltage corresponding to logic “0” and data line D will carry a voltage corresponding to logic “1”. At time t3, the primary latch of sense amplifier 206 is then enabled (e.g., a positive control signal 1065 (e.g., corresponding to ACT 265 shown in FIG. 2B) goes high and the negative control signal 1028 (e.g., corresponding to RnIF 228 shown in FIG. 2B) goes low), which amplifies the differential signal between data lines D and D_ such that the data line D now carries the ANDed result of the respective input data values as determined from the memory cells sensed during the prior operation phases. As such, data line D will be at ground if any of the input data values are a logic “0” and data line D will be at VDD if all of the input data values are a logic “1.”
For an OR operation, if any of the memory cells sensed in the prior operation phases (e.g., the first operation phase of FIG. 7 and one or more iterations of the intermediate operation phase shown in FIG. 9) stored a logic “1” (e.g., if any of the R-inputs of the OR operation were a logic “1”), then the data line D_ will carry a voltage corresponding to logic “0” (e.g., ground) and data line D will carry a voltage corresponding to logic “1” (e.g., VDD). For this OR example, if all of the memory cells sensed in the prior operation phases stored a logic “0” (e.g., all of the R-inputs of the OR operation were logic “0”), then the data line D will carry a voltage corresponding to logic “0” and data line D_ will carry a voltage corresponding to logic “1.” At time t3, the primary latch of sense amplifier 206 is then enabled and the data line D now carries the ORed result of the respective input data values as determined from the memory cells sensed during the prior operation phases. As such, data line D will be at VDD if any of the input data values are a logic “1” and data line D will be at ground if all of the input data values are a logic “0.”
The result of the R-input AND or OR logical operations can then be stored back to a memory cell of array 230 shown in FIG. 2A. In the examples shown in FIG. 10, the result of the R-input logical operation is stored to a memory cell coupled to the last row enabled (e.g., row of the last logical operation operand). Storing the result of the logical operation to a memory cell simply involves enabling the associated row access transistor by enabling the particular row. The capacitor of the memory cell will be driven to a voltage corresponding to the data value on the data line D (e.g., logic “1” or logic “0”), which essentially overwrites whatever data value was previously stored in the selected memory cell. It is noted that the selected memory cell can be a same memory cell that stored a data value used as an input for the logical operation. For instance, the result of the logical operation can be stored back to a memory cell that stored an operand of the logical operation.
The timing diagram illustrated in FIG. 10 shows, at time t7, the positive control signal 1065 and the negative control signal 1028 being deactivated (e.g., signal 1065 goes low and signal 1028 goes high) to disable the sense amplifier 206 shown in FIG. 2A. At time t4 the Passd control signal 1011 (and Passdb signal) that was activated at time t2 is deactivated. Embodiments are not limited to this example. For instance, in a number of embodiments, the sense amplifier 206 shown in FIG. 2A may be enabled subsequent to time t4 (e.g., after the Passd control signal 1011 (and Passdb signal) are deactivated).
As shown in FIG. 10, at time t5, a selected row is enabled (e.g., by row activation signal 1004 going high, which drives the capacitor of the selected cell to the voltage corresponding to the logic value stored in the accumulator. At time t6 the selected row is disabled. At time t7 the sense amplifier 206 shown in FIG. 2A is disabled (e.g., positive control signal 1028 and negative control signal 1065 are deactivated), and at time t8 equilibration occurs (e.g., signal 1026 is activated and the voltages on the complementary data lines 1005-1 (D) and 1005-2 (D_) are brought to the equilibration voltage).
Although the example of performing a last operation phase of an R-input was discussed above with respect to FIG. 10 for performing AND and OR logical operations, embodiments are not limited to these logical operations. For example, the NAND and NOR operations can also involve a last operation phase of an R-input that is stored back to a memory cell of array 230 using control signals to operate the sensing circuitry illustrated in FIG. 2A.
FIG. 11 is a schematic diagram illustrating sensing circuitry having selectable logical operation selection logic in accordance with a number of embodiments of the present disclosure. FIG. 11 shows a sense amplifier 1106 coupled to a pair of complementary sense lines 1105-1 and 1105-2, and a compute component 1131 coupled to the sense amplifier 1106 via pass gates 1193-1 and 1193-2. The gates of the pass gates 1193-1 and 1193-2 can be controlled by a logical operation selection logic signal, PASS, which can be output from logical operation selection logic 1113-5. FIG. 11 shows the compute component 1131 labeled “A” and the sense amplifier 1106 labeled “B” to indicate that the data value stored in the compute component 1131 is the “A” data value and the data value stored in the sense amplifier 1106 is the “B” data value shown in the logic tables illustrated with respect to FIG. 12.
The sensing circuitry 1150 illustrated in FIG. 11 can include logical operation selection logic 1113-5. In this example, the logic 1113-5 comprises swap gates 1142 controlled by a logical operation selection logic signal PASS*. The logical operation selection logic 1113-5 also comprises four logic selection transistors: logic selection transistor 1162 coupled between the gates of the swap transistors 1142 and a TF signal control line, logic selection transistor 1152 coupled between the gates of the pass gates 1193-1 and 1193-2 and a TT signal control line, logic selection transistor 1154 coupled between the gates of the pass gates 1193-1 and 1193-2 and a FT signal control line, and logic selection transistor 1164 coupled between the gates of the swap transistors 1142 and a FF signal control line. Gates of logic selection transistors 1162 and 1152 are coupled to the true sense line (e.g., 1105-1) through isolation transistor 1150-1 (having a gate coupled to an ISO signal control line), and gates of logic selection transistors 1164 and 1154 are coupled to the complementary sense line (e.g., 1105-2) through isolation transistor 1150-2 (also having a gate coupled to an ISO signal control line).
Logic selection transistors 1152 and 1154 are arranged similarly to transistor 507-1 (coupled to an AND signal control line) and transistor 507-2 (coupled to an OR signal control line) respectively, as shown in FIG. 5. Operation of logic selection transistors 1152 and 1154 are similar based on the state of the TT and FT selection signals and the data values on the respective complementary sense lines at the time the ISO signal is asserted. Logic selection transistors 1162 and 1164 also operate in a similar manner to control (e.g., enable by turning on or disable by turning off) the swap transistors 1142. For instance, to enable (e.g., turn on) the swap transistors 1142, either the TF control signal is activated (e.g., high) with data value on the true sense line being “1,” or the FF control signal is activated (e.g., high) with the data value on the complement sense line being “1.” If either the respective control signal or the data value on the corresponding sense line (e.g., sense line to which the gate of the particular logic selection transistor is coupled) is not high, then the swap transistors 1142 will not be enabled by a particular logic selection transistor.
The PASS* control signal is not necessarily complementary to the PASS control signal. For instance, it is possible for the PASS and PASS* control signals to both be activated or both be deactivated at the same time. However, activation of both the PASS and PASS* control signals at the same time shorts the pair of complementary sense lines DIGIT(n)/DIGIT(n)_ together, which may be a disruptive configuration to be avoided. Logical operations results for the sensing circuitry illustrated in FIG. 11 are summarized in the logic table illustrated in FIG. 12.
FIG. 12 is a logic table illustrating selectable logic operation results implementable by the sensing circuitry shown in FIG. 11 in accordance with a number of embodiments of the present disclosure. The four logic selection control signals (e.g., TF, TT, FT, and FF), in conjunction with a particular data value present on the complementary sense lines, can be used to select one of plural logical operations to implement involving the starting data values stored in the sense amplifier 1106 and compute component 1131. The four control signals (e.g., TF, TT, FT, and FF), in conjunction with a particular data value present on the complementary sense lines, controls the pass gates 1193-1 and 1193-2 and swap transistors 1142, which in turn affects the data value in the compute component 1131 and/or sense amplifier 1106 before/after firing. The capability to selectably control the swap transistors 1142 facilitates implementing logical operations involving inverse data values (e.g., inverse operands and/or inverse result), among others.
The logic table illustrated in FIG. 12 shows the starting data value stored in the compute component 1131 shown in column A at 1244, and the starting data value stored in the sense amplifier 1106 shown in column B at 1245. The other 3 top column headings (NOT OPEN 1256, OPEN TRUE 1270, and OPEN INVERT 1271) in the logic table of FIG. 12 refer to the state of the pass gates 1193-1 and 1193-2, and the swap transistors 1142, which can respectively be controlled to be OPEN or CLOSED depending on the state of the four logic selection control signals (e.g., TF, TT, FT, and FF), in conjunction with a particular data value present on the pair of complementary sense lines 1105-1 and 1105-2 when the ISO control signal is asserted. The “Not Open” column corresponds to the pass gates 1193-1 and 1193-2 and the swap transistors 1142 both being in a non-conducting (e.g., off) condition, the “Open True” corresponds to the pass gates 1193-1 and 1193-2 being in a conducting (e.g., on) condition, and the “Open Invert” corresponds to the swap transistors 1142 being in a conducting condition. The configuration corresponding to the pass gates 1193-1 and 1193-2 and the swap transistors 1142 both being in a conducting condition is not reflected in the logic table of FIG. 12 since this results in the sense lines being shorted together.
Via selective control of the pass gates 1193-1 and 1193-2 and the swap transistors 1142, each of the three columns of the first set of two rows of the upper portion of the logic table of FIG. 12 can be combined with each of the three columns of the second set of two rows below the first set to provide 3×3=9 different result combinations, corresponding to nine different logical operations, as indicated by the various connecting paths shown at 1275. The nine different selectable logical operations that can be implemented by the sensing circuitry 1150 are summarized in the logic table illustrated in FIG. 12.
The columns of the lower portion of the logic table illustrated in FIG. 12 show a heading 1280 that can include the state of logic selection control signals. For example, the state of a first logic selection control signal (e.g., FF) is provided in row 1276, the state of a second logic selection control signal (e.g., FT) is provided in row 1277, the state of a third logic selection control signal (e.g., TF) is provided in row 1278, and the state of a fourth logic selection control signal (e.g., TT) is provided in row 1279. The particular logical operation corresponding to the results is summarized in row 1247.
As such, the sensing circuitry shown in FIG. 11 can be used to perform various logical operations as shown in FIG. 12. For example, the sensing circuitry 1150 can be operated to perform various logical operations (e.g., AND and OR logical operations) in association with performing swap operations in a memory in accordance with a number of embodiments of the present disclosure.
The present disclosure can include apparatuses and methods related to performing swap operations in memory. An example apparatus might include a first group of memory cells coupled to a first sense line and configured to store a first element. An example apparatus might include a second group of memory cells coupled to a second sense line and configured to store a second element. An example apparatus might also include a controller configured to cause the first element to be stored in the second group of memory cells and the second element to be stored in the first group of memory cells by controlling sensing circuitry to perform a number operations without transferring data via an input/output (I/O) line.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art will appreciate that an arrangement calculated to achieve the same results can be substituted for the specific embodiments shown. This disclosure is intended to cover adaptations or variations of one or more embodiments of the present disclosure. It is to be understood that the above description has been made in an illustrative fashion, and not a restrictive one. Combination of the above embodiments, and other embodiments not specifically described herein will be apparent to those of skill in the art upon reviewing the above description. The scope of the one or more embodiments of the present disclosure can include other applications in which the above structures and methods are used. Therefore, the scope of one or more embodiments of the present disclosure should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.
In the foregoing Detailed Description, some features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the disclosed embodiments of the present disclosure have to use more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

## Claims

1. An apparatus comprising:
a first group of memory cells coupled to a first sense line and configured to store a first element;
a second group of memory cells coupled to a second sense line and configured to store a second element; and
a controller configured to cause the first element to be stored in the second group of memory cells and the second element to be stored in the first group of memory cells by controlling sensing circuitry to perform a number operations without transferring data via an input/output (I/O) line, wherein the sensing circuitry comprises a first compute component coupled to the first sense line and formed on pitch with the first group of memory cells and a second compute component coupled to the second sense line and formed on pitch with the second group of memory cells and the number of operations comprises a number of AND operations, OR operations, INVERT operations, and SHIFT operations.

2. The apparatus of claim 1, wherein the sensing circuitry comprises a first sense amplifier coupled to the first compute component and a second sense amplifier coupled to the second compute component.

3. The apparatus of claim 2, wherein each of the first and the second sense amplifier comprise a primary latch and each of the first and the second compute component comprises a secondary latch.

4. A method comprising:
performing a swap operation, comprising:
swapping a first element stored in a first group of memory cells coupled to a first sense line and to a number of access lines of an array of memory cells with a second element stored in a second group of memory cells coupled to a second sense line and to the number of access lines, such that subsequent to the swapping, the first element is stored in the second group of memory cells and the second element is stored in the first group of memory cells;

wherein the swapping is performed without transferring data corresponding to the first and second elements via an input/output (I/O) line;
wherein the first element and the second element are a first element pair; and
wherein performing the swap operation comprises swapping multiple element pairs in parallel, with each respective one of the multiple element pairs being stored in memory cells coupled to different sense lines.

5. The method of claim 4, wherein, prior to the swapping, the first element is stored as a first bit-vector in the first group of memory cells, with each memory cell in the first group of memory cells storing a respective bit of the first bit-vector.

6. The method of claim 5, wherein, prior to swapping, the second element is stored as a second bit-vector in the second group of memory cells, with each memory cell in the second group of memory cells storing a respective bit of the second bit-vector.

7. The method of claim 6, wherein, subsequent to the swapping, the first bit-vector is stored in the second group of memory cells and the second bit-vector is stored in the first group of memory cells.

8. The method of claim 4, wherein, prior to the swapping:
the first element is stored, as a first bit-vector comprising a number of bits, in a respective number of memory cells of the first group; and
the second element is stored, as a second bit-vector comprising a same number of bits as the first bit-vector, in a respective number of memory cells of the second group; and
wherein bits of the first bit-vector having a same bit position as bits of the second bit-vector are stored in memory cells coupled to a same access line of the number of access lines; and
wherein swapping the first element with the second element comprises swapping bit pairs of the first and second bit-vectors having a same bit position and stored in memory cells coupled to a same access line such that subsequent to the swapping, the first element is stored, as the first bit-vector, in the respective number of memory cells of the second group, and the second element is stored, as the second bit-vector, in the respective number of memory cells of the first group.

9. The method of claim 4, wherein the first element is a first value and the second element is a second value and wherein performing the swap operation results in storing the first value in the second group of memory cells and storing the second value in the first group of memory cells.

10. An apparatus comprising:
a plurality of first groups of memory cells coupled to a plurality of first sense lines and configured to store a plurality of first elements;
a plurality of second groups of memory cells coupled to a plurality of second sense lines and configured to store a plurality of second elements;
a controller configured to control sensing circuitry to perform a swap operation by storing the plurality of first elements in the plurality of second groups of memory cells and the plurality of second element in the plurality of first groups of memory cells without transferring data via an input/output (I/O) line; and
wherein a quantity of the plurality of first sense lines is a same quantity as a quantity of the plurality of second sense lines, and wherein each of the plurality of second sense lines is adjacent to a different one of the plurality of first sense lines of a memory array.

11. The apparatus of claim 10, wherein no two of the plurality of second sense lines are adjacent to each other.

12. The apparatus of claim 11, wherein no two of the plurality of first sense lines are adjacent to each other.

13. An apparatus comprising:
a plurality of first groups of memory cells configured to store a plurality of first elements, wherein each group from the plurality of first groups of memory cells is coupled to a different sense line from a plurality of first sense lines and to a number of access lines;
a plurality of second groups of memory cells configured to store a plurality of second elements, wherein each group from the plurality of second groups of memory cells is coupled to a different sense line from a plurality of second sense lines and to the number of access lines; and
a controller configured to control sensing circuitry to, without transferring data via an input/output (I/O) line, swap the plurality of first elements with the plurality of second elements such that the plurality of first elements are stored in the plurality of second groups of memory cells and the plurality of second elements are stored in the plurality of first groups of memory cells; and
wherein the controller is further configured to control the sensing circuitry to perform a number of iterations of operations, and wherein the number of iterations is equal to an element width of the first and the second plurality of elements.

14. The apparatus of claim 13, wherein the first and the second plurality of elements are stored as respective bit-vectors, and wherein the element width is a quantity of bits corresponding to the respective bit-vectors.

15. The apparatus of claim 13, further comprising the controller being configured to control the sensing circuitry to perform each of the number of iterations of operations by storing a particular bit from each of the plurality of first elements in memory cells of the plurality of second groups of memory cells and storing a particular bit from each of the plurality of second elements in memory cells of the plurality of first groups of memory cells.

16. A method for performing a swap operation comprising:
performing, in parallel and without performing a sense line address access, a swap operation in memory on:
a plurality (M) of first elements stored in a plurality of first groups of memory cells, wherein each group of memory cells from the plurality of first groups is coupled to a different sense line from a plurality of first sense lines and to a number (X) of access lines;
a plurality (M) of second elements stored in a plurality of second groups of memory cells, wherein each group of memory cells from the plurality of second groups is coupled to a different sense line from a plurality of second sense lines and to the X access lines;

wherein performing the swap operation results in storing the M first elements in the plurality of second groups of memory cells and the M second elements in the plurality of first groups of memory cells;
wherein each of the M first elements and the M second elements are comprised of a number (N) of bits;
wherein each of the N bits in each of the M first elements and the M second elements are associated with one of a number (X) of indices corresponding to bit positions of the N bits, and bits from corresponding elements having a same associated index are stored in memory cells that are coupled to a same access line from the X access line, and each of the X access lines is associated with a different one of the X indices; and
wherein the method further comprises identifying that the swap operation is performed on the plurality of first elements and the plurality of second elements by:
storing a mask bit-vector in a first group of memory cells coupled to a first access line and to a plurality of third sense lines, wherein the plurality of third sense lines includes the plurality of first sense lines and the plurality of second sense lines; and
storing a shifted mask bit-vector in a second group of memory cells coupled to a second access and to the plurality of third sense lines, wherein the mask bit-vector and the shifted mask bit-vector identified which elements from the plurality of first elements and the plurality of second elements are used in the swap operation.

17. The method of claim 16, further comprising, performing a number of iterations of operations wherein each iteration of operations is associated with one of the X indices.

18. The method of claim 17, wherein each iteration of operations of the number of iterations of operations further comprises:
storing a first temporary bit-vector that includes a plurality of bits that are associated with a particular index from the X indices from each of the plurality of first elements and the plurality of second elements in a third group of memory cells that are coupled to a third access line and to the plurality of third sense lines; and
storing the first temp bit-vector in a plurality of compute components.

19. The method of claim 18, wherein each iteration of operations of the number of iterations of operations further comprises:
right shifting a bit-vector stored in the plurality of compute components;
performing a first AND operation on the bit-vector and the shifted mask vector; and
storing the result of the first AND operation as a second temp bit-vector in a fourth group of memory cells;
wherein the fourth group of memory cells are coupled to a fourth access line and to the plurality of third sense lines.

20. The method of claim 19, wherein each iteration of operations of the number of iterations of operations further comprise:
storing the shifted mask bit-vector in the plurality of compute components;
performing a first INVERT operation on the bit-vector stored in the plurality of compute components;
performing a second AND operation on the plurality of bits that are associated with the particular index from the X indices from each of the plurality of first elements and the plurality of second elements and on the bit-vector stored in the plurality of compute components;
performing a first OR operation on the result of the second AND operation and on the second temp bit-vector;
storing the result of the first OR operation in memory cells that are coupled to an access line that is associated with the particular index and the X sense lines.

21. The method of claim 20, wherein each iteration of operations of the number of iterations of operations further comprise:
storing the first temp bit-vector in the plurality of compute components;
performing a third AND operation on the bit-vector stored in the plurality of compute components and on the shifted mask vector;
storing the result of the third AND operation in the compute components;
left shifting the bit-vector in the compute component;
storing the bit-vector in the compute components in the fourth group of memory cells.

22. The method of claim 21, wherein each iteration of operations of the number of iterations of operations further comprise:
storing the mask bit-vector in the plurality of compute components;
performing a second INVERT operation on the bit-vector stored in the plurality of compute components;
performing a fourth AND operation on the bit-vector stored in the plurality of compute components and the plurality of bits that are associated with the particular index from the X indices from each of the plurality of first elements and the plurality of second elements;
performing a second OR operation on a result of the fourth AND operation and the second temp bit-vector;
storing a result of the second OR operation in memory cells that are coupled to the access line that is associated with the particular index and the X sense lines.