Patent Publication Number: US-11651802-B1

Title: Systems and methods for dual standby modes in memory

Description:
TECHNICAL FIELD 
     Embodiments of the present disclosure relate to, among other things, systems and methods for operating a memory device in multiple standby modes, including a read standby mode and a write standby mode. 
     INTRODUCTION 
     In general, a memory system may include a memory device for storing data and a host (or controller) for controlling operations of the memory device. Memory devices may be classified into volatile memory (such as, e.g., dynamic random-access memory (DRAM), static random-access memory (SRAM), etc.) and non-volatile memory (such as, e.g., electrically erasable programmable read-only memory (EEPROM), ferroelectric random-access memory (FRAM), phase-change memory (PRAM), magnetoresistive memory (MRAM), resistive random-access memory (RRAM/ReRAM), flash memory, etc.). 
     Spin-torque magnetic memory devices store information by controlling the resistance across a magnetic tunnel junction (MTJ) such that a read current through the MTJ results in a voltage drop having a magnitude that is based on the state of the magnetoresistive stack. The resistance in each MTJ can be varied based on the relative magnetic states of the magnetoresistive layers within the magnetoresistive stack. In such memory devices, there is typically a portion of the magnetoresistive stack that has a fixed magnetic state and another portion that has a free magnetic state that is controlled to be either of two possible states relative to the portion having the fixed magnetic state. Because the resistance through the MTJ changes based on the orientation of the free portion relative to the fixed portion, information can be stored by setting the orientation of the free portion. The information is later retrieved by sensing the orientation of the free portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the course of the detailed description that follows, reference will be made to the appended drawings. The drawings show different aspects of the present disclosure and, where appropriate, reference numerals illustrating like structures, components, materials, and/or elements in different figures are labeled similarly. It is understood that various combinations of the structures, components, and/or elements, other than those specifically shown, are contemplated and are within the scope of the present disclosure. 
       Moreover, there are many embodiments of the present disclosure described and illustrated herein. The present disclosure is neither limited to any single aspect nor embodiment thereof, nor to any combinations and/or permutations of such aspects and/or embodiments. Moreover, each of the aspects of the present disclosure, and/or embodiments thereof, may be employed alone or in combination with one or more of the other aspects of the present disclosure and/or embodiments thereof. For the sake of brevity, certain permutations and combinations are not discussed and/or illustrated separately herein; however, all permutations and combinations are considered to fall within the scope of the present inventions. 
         FIG.  1    depicts an example NOR memory device. 
         FIG.  2    depicts a block diagram of an exemplary memory device, according to an aspect of the present disclosure. 
         FIG.  3    depicts a flowchart for an exemplary method of operating a memory device, according to an aspect of the present disclosure. 
         FIG.  4 A  depicts a chart of a memory system under a read bias mode, according to an aspect of the present disclosure. 
         FIG.  4 B  depicts a chart of a memory system under a write bias mode, according to an aspect of the present disclosure. 
         FIG.  5    depicts a flowchart for using machine learning to output an operation mode, according to an aspect of the present disclosure. 
         FIG.  6    depicts a block diagram of yet another exemplary MRAM device, according to an aspect of the present disclosure. 
         FIG.  7    depicts a block diagram of an exemplary computing device that may execute techniques described in the present disclosure. 
     
    
    
     Again, there are many embodiments described and illustrated herein. The present disclosure is neither limited to any single aspect nor embodiment thereof, nor to any combinations and/or permutations of such aspects and/or embodiments. Each of the aspects of the present disclosure, and/or embodiments thereof, may be employed alone or in combination with one or more of the other aspects of the present disclosure and/or embodiments thereof. For the sake of brevity, many of those combinations and permutations are not discussed separately herein. 
     DETAILED DESCRIPTION 
     Detailed illustrative aspects are disclosed herein. However, specific structural and functional details disclosed herein are merely representative for purposes of describing example embodiments of the present disclosure. The present disclosure may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments described herein. 
     When the specification makes reference to “one embodiment” or to “an embodiment,” it is intended to mean that a particular feature, structure, characteristic, or function described in connection with the embodiment being discussed is included in at least one contemplated embodiment of the present disclosure. Thus, the appearance of the phrases, “in one embodiment” or “in an embodiment,” in different places in the specification does not constitute a plurality of references to a single embodiment of the present disclosure. 
     As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It also should be noted that in some alternative implementations, the features and/or steps described may occur out of the order depicted in the figures or discussed herein. For example, two steps or figures shown in succession may instead be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. In some aspects, one or more described features or steps may be omitted altogether, or may be performed with an intermediate step therebetween, without departing from the scope of the embodiments described herein, depending upon the functionality/acts involved. 
     It should be noted that the description set forth herein is merely illustrative in nature and is not intended to limit the embodiments of the subject matter, or the application and uses of such embodiments. Any implementation described herein as exemplary is not to be construed as preferred or advantageous over other implementations. Rather, the term “exemplary” is used in the sense of example or “illustrative,” rather than “ideal.” The terms “comprise,” “include,” “have,” “with,” and any variations thereof are used synonymously to denote or describe a non-exclusive inclusion. As such, a device or a method that uses such terms does not include only those elements or steps, but may include other elements and steps not expressly listed or inherent to such device and method. Further, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Similarly, terms of relative orientation, such as “top,” “bottom,” etc. are used with reference to the orientation of the structure illustrated in the figures being described. 
     Serial Peripheral Interface (SPI) NOR based products can be implemented using a standby mode. During a standby mode, such SPI NOR products may receive a read or write program command. The SPI NOR products may be ready with bias voltages in a memory array such that a read or write command can be serviced without extra time being expended to reach the read and write bias voltages needed for NOR memory array read and/or write operations. In such SPI NOR products, wakeup time of read and write bias voltages are 100s of micro seconds, depending on memory density. The wakeup time may be accounted for in the power up time needed while powering up a memory product using an external power supply. The wakeup time may be accounted for in deep power down mode exit time. The read and write bias system of such SPI NOR products consume a read and write bias current to generate the voltages needed for memory array read and the write operations. Read and write bias currents may be consumed when an SPI NOR product is in standby mode. 
       FIG.  1    depicts an example NOR memory device  100 . NOR memory device  100  in  FIG.  1    includes a joint read and write bias system  101 . Read and write bias system  101  may draw standby current to provide read and write bias voltages to the NOR memory array  102  during standby operation. The standby voltage may be sufficient to facilitate both read and write operations. For example, the standby voltage may be sufficient to facilitate a read operation by NOR memory array  102 . The standby voltage may enable NOR memory array  102  to receive a read command, draw an active operation current, and perform the read operation. Similarly, the same standby voltage may enable NOR memory array  102  to receive a write command, draw an active operation current, and perform the write operation. Accordingly, read and write bias system  101  may draw a standby current large enough to provide read and write bias voltages for supporting both read and write operations. Standby current draw in bias system  101  is an issue for NOR memory device  100  application in low power systems. 
     Implementations of the disclosed subject matter reduce standby voltage generation in memory products using multiple standby modes. For example, implementations of the disclosed subject matter address standby voltage reduction in SPI NOR-like products (e.g., memory products that operate, at least in part, in a manner similar to SPI NOR products). The SPI NOR-like products may be a spin-transfer torque magnetoresistive memory (STT-MRAM) products or any other memory products that can be configured to include multiple standby modes using multiple bias systems (e.g., a read bias system and a write bias system). 
     In one aspect, the present disclosure is directed to techniques and implementations to lower standby current draw associated with bias voltage generation via multiple standby modes such as a fast read standby mode and a read plus write standby mode. Though the description below makes reference to MRAM devices, the inventions may be implemented in other memory devices including, but not limited to, EEPROM, FRAM, PRAM, RRAM/ReRAM and/or flash memory. 
     MRAM devices and other memory devices often include an array of memory cells divided into a plurality of banks or subarrays. In such memory devices, each bank can be accessed separately such that accesses between banks can be interleaved to optimize data throughput. Some magnetic memory devices support dual data rate (DDR) memory protocols. 
       FIG.  2    depicts a block diagram of an exemplary memory system  200  (e.g., MRAM device), in accordance with the subject matter disclosed herein. Memory system  200  includes a first MRAM array  202 A and a second MRAM array  202 B (e.g., array banks). Although two array banks are shown in  FIG.  2   , it will be understood that the techniques disclosed herein may be implemented using any number of array banks (i.e., one or more array banks). MRAM array  202 A may have an address decoder  214 A and MRAM array  202 B may have an address decoder  214 B. Address decoders  214 A and  214 B may be configured to decode a read or write request to identify a memory location that corresponds to the read or write request (e.g., an address). MRAM arrays  202 A and  202 B may be biased with a read bias voltage, write bias voltage, active voltage, or no voltage. MRAM arrays  202 A and/or  202 B biased with no voltage may be in an off state such that any read or write requests may not be fulfilled. MRAM arrays  202 A and/or  202 B biased with a read bias voltage may draw an active read voltage upon receipt of a read command. MRAM arrays  202 A and/or  202 B biased with a write bias voltage may require write bias system  212  to draw a write bias voltage and may further draw an active write voltage upon receipt of a write command. 
     Read bias system  210  may be connected to MRAM array  202 A and  202 B. Read bias system  210  may be configured to provide a read standby bias voltage to MRAM array  202 A and  202 B during standby operation. Read bias system  210  may generate a voltage equal to or less than a supply voltage (e.g., 1.8 V) for operation during a standby mode. Read bias system  210  may receive a control signal from control  208 . Based on control  208 , read bias system  210  may be configured to enter a standby mode and may draw a corresponding current from the supply voltage (e.g., 1.8 V) during standby mode operation. For example, read bias system  210  may be configured to generate between 1.5V and 1.8V during standby mode. Read bias voltage level (e.g., between 1.5V and 1.8V) generated by the read bias system  210  is necessary for read operation in MRAM Array  202 A and  202 B when a read operation command is received by memory system  200 . 
     Write bias system  212  may be connected to MRAM array  202 A and  202 B. Write bias system  212  may be configured to provide a write standby voltage to MRAM array  202 A and  202 B during standby operation. Write bias system  212  may generate a voltage greater than a supply voltage (e.g., a write bias voltage of 2.0 V) for operation during a write standby mode. For example, write bias system  212  may generate a write bias voltage of 2.0V that is greater than a supply voltage of 1.8V, during a write bias mode. Write bias system  212  may receive a control signal from control  208 . Based on control  208 , write bias system  212  may be configured to enter a write standby mode and may draw a corresponding current during the write standby mode operation. For example, write bias system  212  may be configured to generate between 2.0V and 2.8V. Write bias voltage level (e.g., between 2.0V and 2.8V) generated by write bias system  210  may be necessary for write operation in MRAM Array  202 A and  202 B when a write operation command is received by memory system  200 . 
     Read bias system  210  may provide MRAM arrays  202 A and/or  202 B a read bias voltage during either a read standby mode or a write standby mode. Write bias system  212  may provide MRAM arrays  202 A and/or  202 B a write bias voltage during a write standby mode and may not generate the necessary write bias voltage level during a read standby mode. Accordingly, control  208  may transmit a signal for operation under a read standby mode and read bias system  210  may receive the transmitted signal. Read bias system  210  may generate a read bias voltage (e.g., less than or equal to a supply voltage). The read bias voltage may be used by MRAM arrays  202 A and/or  202 B to transition into an active read mode upon receiving a read command from control  208 . 
     Control  208  may transmit a signal for operation under a write standby mode and read bias system  210  and write bias system  212  may receive the transmitted signal. Read bias system  210  may generate a read bias voltage (e.g., less than or equal to a supply voltage) and write bias system  212  may generate a write bias voltage (e.g., greater than a supply voltage). The read bias voltage and/or write bias voltage may be used by MRAM arrays  202 A and/or  202 B to transition into an active respective read or write modes upon receiving a corresponding command from control  208 . 
     Read bias system  210  may be physically distinct from the write bias system  212  such that the components (e.g., circuitry) of the read bias system  210  may be different than the components of the write bias system  212 . Read bias system  210  may be smaller than write bias system  212 . Read bias system  210  may include a read wordline, a read column selection, a read bitline voltage, etc., each of which may be physically distinct from write bias system  212 &#39;s write wordline, write column selection, write bitline voltage, etc. For example, a write operation may require higher bias voltages than a supply voltage. Down (e.g., write 0) and up (e.g., write 1) may require precise temperature-controlled voltages from a charge pump or may be regulated down from a pumped voltage. Accordingly, write bias circuitry may be more complex than read bias circuitry. Read and write bias voltages provided by read bias system  210  and write bias system  212 , respectively, may be voltages that are applied to read and write NMOS transistor follower circuitry for read and write drivers in MRAM arrays  202 A and/or  202 B. 
     Control  208  may receive command signals from a component such as a serial interface  204 . Serial interface  204  may also configure a standby mode configuration register  206 . Serial interface  204  may configure standby mode configuration register  206  directly or via control  208 . Standby mode configuration register  206  may store a current standby mode for memory system  200  at any given time. Standby mode configuration register  206  may store a current standby mode via any applicable manner such as a standby mode configuration bit. For example, a standby mode configuration bit having a binary true (i.e., “1”) value may correspond to either a read standby mode or a write standby mode and standby mode configuration bit having a binary false (i.e., “0”) value may correspond to the other of the read standby mode or write standby mode. Standby mode configuration bit may be a nonvolatile configuration register bit that may be set and/or reset by control  208 . Control  208  may have access to the given configuration (i.e., read standby mode or write standby mode) based on the standby mode configuration register  206 , and may detect a change in the configuration bit. 
     Accordingly, the memory system  200  may be configured with a read bias system  210  and a write bias system  212  that allow for a relatively faster operation during a read bias mode using up to an available supply voltage. During a read bias mode (e.g., as determined based on a standby mode configuration bit), the circuitry of the write bias system  212  may be deactivated. During the read bias mode, read commands may be processed and MRAM array  202 A and/or  202 B (e.g., STT-MRAM arrays) may be accessed for a read operation without a substantial bias wake time (e.g., less than 100 microseconds). During the read bias mode, a received write command may require powering up write bias system  212  before accessing MRAM array  202 A and/or  202 B for the write operation. Accordingly, the wake up time may be added to the total write operation if a write command is received during a read bias mode. The amount of time for activation of MRAM array  202 A and/or  202 B may be determined based on whether memory system  200  is in a read standby mode or a write standby mode (i.e., the configuration of read bias system  210  and write bias system  212 ) and whether the activation is based on a write command or a read command. 
     Serial interface  204  may be configured to provide a signal indicating a write standby mode or a read standby mode based on a given application that MRAM array  202 A and/or  202 B is used for. For example, during a code storage application, code may be written to MRAM array  202 A and/or  202 B one time and may be read repeatedly. Based on the MRAM array  202 A and/or  202 B being used for a code storage application, standby mode configuration register  206  may be updated to reflect a read standby mode to allow for fast read operations than is the case with conventional, joint read and write bias systems  101 . Write bias system  212  is disabled in a read standby mode resulting in lower standby current draw by memory system  200 . 
     As another example, during a data storage application, data may be written and re-written to MRAM array  202 A and/or  202 B. Previous data may be updated based on, for example, calculations, operations, updates, or the like. Based the MRAM array  202 A and/or  202 B being used for a data storage application, standby mode configuration register  206  may be updated to reflect a write standby mode. Read bias system  210  and write bias system  212  may both be enabled during write standby mode. In an alternate embodiment, only the write bias system  212  may be enabled in a write standby mode. 
     A machine learning model may be used to configure standby mode configuration register  206 , as further disclosed herein. The machine learning model may output one of the read standby mode or write standby mode based on one or more of an application, historical use, or the like. 
       FIG.  3    depicts a flowchart for an exemplary method  300  of operating a memory device (e.g., an MRAM device). Method  300  may be performed by memory system  200  illustrated in  FIG.  2   . At  302 , a first standby mode indication may be received for selecting a first standby mode from a first standby mode or a second standby mode. The first standby mode indication may be either a read standby mode or a write standby more. The first standby mode indication may be received at read bias system  210  and write bias system  212  of  FIG.  2   . The first standby mode indication may be provided by control  208  based on a bit configuration at standby mode configuration register  206 . The bit configuration may be determined based on an input from serial interface  204  and/or a machine learning model. 
     At  304 , read bias system  210  may be configured with a read bias voltage and write bias system  212  may be disabled, configured to provide approximately no voltage or voltage outside (e.g., below) the range for write operations, based on the first standby mode at  302  corresponding to a read bias mode. The read bias voltage may be less than or equal to a supply voltage (e.g., approximately 1.5 V-1.8 V). Read bias system  210  may require less voltage than the supply voltage to maintain a read standby state at least in part due to less complex circuitry associated with read bias system  210 . Accordingly, memory system  200  may operate in a fast read standby mode by utilizing a low voltage (e.g., a supply voltage or less) without a substantial read bias wake time. Memory system  200  may have less current draw in a read standby mode as the write bias system  212  is disabled. 
     At  306 , a second standby mode indication may be received for selecting a second standby mode from a first standby mode or a second standby mode. The second standby mode indication may correspond to a write standby mode. The second standby mode indication may be received at read bias system  210  and write bias system  212  of  FIG.  2   . The second standby mode indication may be provided by control  208  based on a bit configuration at standby mode configuration register  206 . The bit configuration may be determined based on an input from serial interface  204  and/or a machine learning model. 
     At  308 , read bias system  210  may be configured with a read bias voltage and write bias system  212  may be configured with a write bias voltage, based on the second standby mode at  306  corresponding to a write bias mode. The read bias voltage may be less than or equal to a supply voltage (e.g., approximately 1.5 V-1.8 V) and the write bias voltage may be greater than the supply voltage. Memory system  200  may operate in a write standby mode by utilizing a low voltage (e.g., a supply voltage or less) for the read bias system  210  and a higher voltage for the write bias system  212 . Accordingly, read operations in a read standby mode may require less overall voltage (i.e., only the voltage required by read bias system  210 ) than read operations in write standby mode (i.e., the voltage required by read bias system  210  and write bias system  212 ). 
       FIG.  4 A  shows an example chart  400  showing a read standby mode operation having time as its X-axis  404  and voltage as its Y-axis  402 . During the read standby mode, a read operation  408 A and a write operation  406 A may be implemented. Read standby voltage generated by read bias system  210  may be V 1  and may be equal to or less than a supply voltage. The standby voltage drawn by a memory system during the read standby mode may equal the read standby voltage V 1 . During the read standby mode, a read operation command may be received at T 1 . Based on the read operation command, one or more memory arrays may transition to an active mode and may draw an active read voltage V 2 . As shown, the transition from the standby read voltage V 1  to active read voltage V 2  may be nearly immediate. In the preferred embodiment, standby read voltage V 1  is the same as or very close to active read voltage V 2  such that there is no transition delay. Accordingly, during read standby mode, by using read bias system  210  separate from write bias system  212 , the voltage draw of a memory system may be V 1  and read operations may be implemented without a substantial bias wake time. 
     During the read standby mode, write operation  406 A may include a write standby voltage of V 0  (e.g., approximately no voltage or any voltage outside the range necessary for write operation) provided by write bias system  212 . During the read standby mode, a write operation command may be received at T 1 . Based on the write operation command, one or more memory arrays may transition to an active mode and may draw an active write voltage V 3 . The active write voltage may be reached at T 2 . As shown, the transition from the standby write voltage V 0  to active write voltage V 3  may require a time duration equal to T 2 −T 1 , which may be substantially greater than the nearly immediate transition of the voltage from the read standby voltage V 1  to the active read voltage V 2  during the read standby mode. Accordingly, during read standby mode, by using read bias system  210  separate from write bias system  212 , the voltage draw of a memory system may be V 1  and write operations may be implemented with a substantial bias wake time. 
       FIG.  4 B  shows an example chart  420  showing a write standby mode operation having time as its X-axis  404  and voltage as its Y-axis  402 . During the write standby mode, a read operation  408 B and a write operation  406 B may be implemented. Read standby voltage may be V 1  and may be equal to or less than a supply voltage. The standby voltages drawn by a memory system during the write standby mode may equal the read standby voltage V 1  along with a write standby voltage V 3  that is greater than read standby voltage V 1 . During the write standby mode, a read operation command may be received at T 1 . Based on the read operation command, one or more memory arrays may transition to an active mode and may draw an active read voltage V 2 . As shown, the transition from the standby read voltage V 1  to active read voltage V 2  may be nearly immediate. In the preferred embodiment, standby read voltage V 1  is approximately the same as the active read voltage V 2  such that there is no transition delay. 
     During the write standby mode, write operation  406 B may include a write standby voltage of V 3  provided by write bias system  212 . During the write standby mode, a write operation command may be received at T 1 . Based on the write operation command, one or more memory arrays may transition to an active mode and may draw an active write voltage V 4 . As shown, the transition from the standby write voltage V 3  to active write voltage V 4  may be nearly immediate. In the preferred embodiment, standby write voltage V 3  is approximately the same as the active write voltage V 4  such that there is no transition delay. 
     Accordingly, during a write standby mode, a memory system may draw more voltages than during a read standby mode. Further, during the write standby mode, a memory array may transition from a standby voltage to an active write voltage faster than the memory array transitions from a standby to an active write voltage during a read standby mode. 
       FIG.  5    depicts a flowchart  500  for using machine learning to determine and output an operation mode. At  502 , historical application data may be received. The historical application data may correspond to the types of applications that memory system  200  is used to implement. The historical application data may include the types of applications that have historically been used by memory system  200 . More specifically, historical application data may identify write operations versus read operations implemented historically by applications using memory system  200 . It will be understood that though the historical application is disclosed herein for memory system  200 , the historical application data may correspond to any memory system that can be used to predict the use of a given memory system  200 . 
     According to an implementation, historical application data may include read and/or write operation data for a given application. For example, memory system  200  may be slotted for use for a given application (e.g., a code storage application, data storage application, etc.). Accordingly, the historical application data may include data regarding the number, types, sequence, frequency, or the like of read and/or write operations historically implemented by the given application for one or more memory systems. 
     A machine learning model may be trained based on the historical application data (e.g., using supervised or semi-supervised learning). According to implementations, the machine learning model may be trained or additionally trained based on unsupervised learning. For example, the machine learning model may receive the historical application data, one or more applications to be implemented using a memory system, and the like. At  504 , the machine learning model may be trained using the historical application data or one or more other techniques further disclosed herein. 
     At  506 , the machine learning model may output a standby mode (e.g., a read standby mode or a write standby mode), based on one or more inputs including an application, application type, task, user, software, etc. The output may be provided to control  208  and/or standby mode configuration register  206 . The output may be based on the likelihood of a number of read operations or write operations to be performed by a memory system, the frequency of read or write operations, the timing of read or write operations, or the like. The output may be updated over time based on updated inputs (e.g., updated application, application status, application type, task, user, software, etc.). 
     At  508 , a configuration bit at the standby mode configuration register  206  may be set based on the output (e.g., set to 0 or 1 based on a read standby mode output or a write standby mode output). The configuration bit may be set, for example, based on a signal received from control  208 . At  510 , read bias system  210  and/or write bias system  212  may be configured based on the configuration bit set at  508 . 
     The machine learning model disclosed herein may be trained using the data flow  600  of  FIG.  6   . As shown in  FIG.  6   , training data  612  may include one or more of stage inputs  614  and known outcomes  618  related to a machine learning model to be trained. The stage inputs  614  may be from any applicable source including a controller, a processor, a software, a step from method  300  of  FIG.  3   , or the like or a combination thereof. The known outcomes  618  may be included for machine learning models generated based on supervised or semi-supervised training. For example, known outcomes  618  may be based on historical application data. An unsupervised machine learning model may not be trained using known outcomes  618 . Known outcomes  618  may include known or desired outputs for future inputs similar to or in the same category as stage inputs  614  that do not have corresponding known outputs. 
     The training data  612  and a training algorithm  620  may be provided to a training component  630  that may apply the training data  612  to the training algorithm  620  to generate a machine learning model. The machine learning model may be generated by adjusting one or more weights or one or more layers of an untrained model. According to an implementation, the training component  630  may be provided comparison results  616  that compare a previous output of the corresponding machine learning model to apply the previous result to re-train the machine learning model. The comparison results  616  may be used by the training component  630  to update the corresponding machine learning model. The training algorithm  620  may utilize machine learning networks and/or models including, but not limited to a deep learning network such as Deep Neural Networks (DNN), Convolutional Neural Networks (CNN), Fully Convolutional Networks (FCN) and Recurrent Neural Networks (RCN), probabilistic models such as Bayesian Networks and Graphical Models, and/or discriminative models such as Decision Forests and maximum margin methods, or the like. 
       FIG.  7    depicts an example system  700  that may execute techniques presented herein.  FIG.  7    is a simplified functional block diagram of a computer that may be configured to execute techniques described herein, according to exemplary embodiments of the present disclosure. Specifically, the computer (or “platform” as it may not be a single physical computer infrastructure) may include a data communication interface  760  for packet data communication. The platform may also include a central processing unit (“CPU”)  720 , in the form of one or more processors, for executing program instructions. The platform may include an internal communication bus  710 , and the platform may also include a program storage and/or a data storage for various data files to be processed and/or communicated by the platform such as ROM  730  and RAM  740 , although the system  700  may receive programming and data via network communications. Any of ROM  730  or RAM  740  may comprise of MRAM devices or any other memory devices including but not limited to EEPROM, FRAM, PRAM, RRAM/ReRAM and/or flash memory. The system  700  also may include input and output ports  750  to connect with input and output devices such as keyboards, mice, touchscreens, monitors, displays, etc. Of course, the various system functions may be implemented in a distributed fashion on a number of similar platforms, to distribute the processing load. Alternatively, the systems may be implemented by appropriate programming of one computer hardware platform. 
     The particular embodiments disclosed above are illustrative only and should not be taken as limitations, as the embodiments may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Accordingly, the foregoing description is not intended to limit the disclosure to the particular form set forth, but on the contrary, is intended to cover such alternatives, modifications and equivalents as may be included within the spirit and scope of the inventions as defined by the appended claims so that those skilled in the art should understand that they can make various changes, substitutions and alterations without departing from the spirit and scope of the inventions in their broadest form. 
     In one embodiment, a method for accessing memory using dual standby modes is disclosed. The method may comprise: receiving a first standby mode indication selecting a first standby mode from a first standby mode or a second standby mode; configuring a read bias system to provide a read bias voltage and a write bias system to provide approximately no voltage or any voltage below a voltage range for write operation, based on the first standby mode; receiving a second standby mode indication selecting the second standby mode; and configuring the read bias system to provide at least the read bias voltage and the write bias system to provide a write bias voltage based on the second standby mode, the read bias voltage being lower than the write bias voltage. 
     Various embodiments of the method may comprise, without limitation: receiving a read command or a write command and activating a memory bank based on the read command or the write command, an amount of time for activation of the memory bank being determined based on the read command or the write command and on the configuration of the read bias system and the write bias system; wherein an amount of time to activate a memory bank for a write operation is greater during the first standby mode than during the second standby mode; wherein each of the first standby mode indication and the second standby mode indication is based on a configuration bit at a standby mode configuration register; wherein the read bias voltage is approximately in the range of 1.5V to 1.8V; wherein the read bias voltage is less than or equal to a standby supply voltage; wherein the write bias voltage is approximately in the range of 2.0V to 2.8V; wherein the write bias voltage is greater than or equal to a standby supply voltage; wherein the first standby mode indication or the second standby mode indication is received based on historical controller commands; wherein the historical controller commands are input to a machine learning model that outputs the first standby mode indication or the second standby mode indication; and wherein the first standby mode indication or the second standby mode indication is received based on a voltage application. 
     In another embodiment, a system for accessing memory using dual standby modes is disclosed. The system may comprise: a memory array; a read bias system; a write bias system physically distinct from the read bias system; a standby mode configuration register; and a controller. The controller is configured to: provide a standby signal to the read bias system and the write bias system based on a configuration bit at the standby mode configuration register, the configuration bit indicating a first standby configuration from a first standby configuration or a second standby configuration, the read bias system configured to provide a read bias voltage based on the first standby configuration and the write bias system configured to provide approximately no voltage, or any voltage below a voltage range for write operation, based on the first standby configuration; provide a read command or a write command to the memory array; detect a change in the configuration bit to indicate a second standby configuration; and provide an updated standby signal to the read bias system and the write bias system based on the change in the configuration bit, the read bias system configured to provide a read bias voltage based on the second standby configuration and the write bias system configured to provide a write bias voltage based on the second standby configuration. 
     Various embodiments of the system may comprise, without limitation: wherein the read bias system provides a lower voltage for operation than the write bias system; wherein the read bias voltage is approximately in the range of 1.5V to 1.8V; wherein the read bias voltage is less than or equal to a standby supply voltage; wherein the write bias voltage is approximately in the range of 2.0V to 2.8V; wherein the write bias voltage is greater than or equal to a standby supply voltage; wherein the first standby mode indication or the second standby mode indication is received based on historical controller commands; and wherein the memory array is a magnetoresistive memory (MRAM) array. 
     In yet another embodiment, a non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform operations for accessing memory using dual standby modes is disclosed. The operations may comprise: receiving a first standby mode indication selecting a first standby mode from a first standby mode or a second standby mode; configuring a read bias system to provide a read bias voltage and a write bias system to provide approximately no voltage, or any voltage below a voltage range for write operation, based on the first standby mode; receiving a second standby mode indication selecting the second standby mode; and configuring the read bias system to provide at least the read bias voltage and the write bias system to provide a write bias voltage based on the second standby mode, the read bias voltage being lower than the write bias voltage. 
     The foregoing description of the inventions has been described for purposes of clarity and understanding. It is not intended to limit the inventions to the precise form disclosed. Various modifications may be possible within the scope and equivalence of the application.