Memory system for controlling input command priority and operation method therefor

A memory system may include: a controller suitable for checking a priority information on a plurality of input commands, storing the input commands having a high priority information as a first command in a first command storage unit, and storing the input commands having a low priority information as a second command in a second command storage unit, and one or more memory device suitable for operating in response to the input commands stored in the first or second command storage units.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2015-0164550 filed on Nov. 24, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND

Exemplary embodiments of the present invention relate to a semiconductor design technology and, more particularly, to a memory system capable of effectively managing a plurality of commands provided from a host, and an operation method thereof.

2. Description of the Related Art

The computer environment paradigm has shifted to ubiquitous computing systems that may be used anytime and anywhere. Due to this, the use of portable electronic devices such as mobile phones, digital cameras, and notebook computers has rapidly increased. Portable electronic devices generally employ a memory system having one or more semiconductor memory devices used as main or auxiliary data storage devices.

Semiconductor memory devices generally provide excellent stability, durability, high information access speed, and low power consumption, since they have no moving parts. Well-known examples of semiconductor memory devices include universal serial bus (USB) memory devices, memory cards having various interfaces, and solid state drives (SSD).

SUMMARY

Various embodiments are directed to a memory system which is capable of prioritizing the execution of a plurality of commands, and an operating method thereof.

In an embodiment, a memory system may include: a controller suitable for checking a priority information on a plurality of input commands, storing the input commands having a high priority information as a first command in a first command storage unit, and storing the input commands having a low priority information as a second command in a second command storage unit; and one or more memory device suitable for operating in response to the input commands stored in the first or second command storage units.

The high priority information may request a compulsory change of an execution sequence, regardless of an input order of the input commands.

The low priority information may request that the input commands are sequentially executed according to the input order of the input commands, while requesting a flexible change of the execution sequence.

The controller may manage the first command stored in the first command storage unit in the form of a linked-list, and may manage the second command stored in the second command storage unit in the form of a tree-list.

The low priority information may include: a sequential information requesting that the input commands are sequentially executed according to the input order of the input commands; and a flexible information requesting the flexible change of the execution sequence such that the input commands are executed prior to a command having the sequential information.

The controller may store the second command having the sequential information in the second command storage unit at a level of the tree-list, which is lower than that of the second command having the flexible information.

The controller may manage the level of the tree-list of the second command having the sequential information based on logical address values corresponding thereto, and may manage the level of the tree-list of the second command having the flexible information based on logical address values corresponding thereto.

The controller may transfer the second command having the sequential information, which is not executed within a preset time after being stored in the second command storage unit, to a level of the tree-list, which is higher than that of the second command having the flexible information.

The high priority information may include: an order information requesting that the input commands must be executed prior to a command having the low priority information; and a head information requesting that the input commands must be first executed.

The controller may transmit a command stored in the first command storage unit to the memory devices, prior to a command stored in the second command storage unit.

In an embodiment, an operating method of a memory system including one or more memory device, the operating method may include: checking a priority information on a plurality of input commands; and storing the input commands having a high priority information as a first command in a first command storage unit, storing the input commands having a low priority information as a second command in a second command storage unit, and transmitting the input commands stored in the first or second command storage units for operating the memory devices.

The high priority information may request a compulsory change of an execution sequence, regardless of an input order of the input commands.

The low priority information may request that the input commands are sequentially executed according to the input order of the input commands, while requesting a flexible change of the execution sequence.

The storing of the input commands may further include: managing the first command stored in the first command storage unit in the form of a linked-list, and managing the second command stored in the second command storage unit in the form of a tree-list.

The low priority information may include: a sequential information requesting that the input commands are sequentially executed according to the input order of the input commands; and a flexible information requesting the flexible change of the execution sequence such that the input commands are executed prior to a command having the sequential information.

The managing of the second command may include storing the second command having the sequential information in the second command storage unit at a level of the tree-list, which is lower than that of the second command having the flexible information.

The managing of the second command may further include: managing the level of the tree-list of the second command having the sequential information based on logical address values corresponding thereto, and managing the level of the tree-list of the second command having the flexible information based on logical address values corresponding thereto.

The managing of the second command may further include transferring the second command having the sequential information, which is not executed within a preset time after being stored in the second command storage unit, to a level of the tree-list, which is higher than that of the second command having the flexible information.

The high priority information may include: an order information requesting that the input commands must be executed prior to a command having the low priority information; and a head information requesting that the input commands must be first executed.

The transmitting of the input commands may include transmitting a command stored in the first command storage unit to the memory devices, prior to a command stored in the second command storage unit.

DETAILED DESCRIPTION

Referring now toFIG. 1, a data processing system100is provided, according to an embodiment of the present invention. The data processing system100may include a host102and a memory system110.

The host102may include any suitable electronic device. For example, the host102may include a portable electronic device such as a mobile phone, an MP3 player, a laptop computer and the like. The host may include a non-portable electronic device such as a desktop computer, a game player, a TV, a projector and the like.

The memory system110may store data to be accessed by the host102in response to a request from the host102. The memory system110may be used as a main memory system or an auxiliary memory system of the host102. The memory system110may be implemented to be coupled electrically with the host102, according to a protocol of a host interface. One or more semiconductor memory devices may be used. Volatile or non-volatile memory devices may be used. For example, the memory system110may be implemented with a solid state drive (SSD), a multimedia card (MMC), an embedded MMC (eMMC), a reduced size MMC (RS-MMC) and a micro-MMC, a secure digital (SD) card, a mini-SD and a micro-SD, a universal serial bus (USB) storage device, a universal flash storage (UFS) device, a compact flash (CF) card, a smart media (SM) card, a memory stick, and the like.

The memory system110may include a memory device150for storing data and a controller130for controlling storage of data in the memory device150. The stored data in the memory device150may be accessed by the host102.

The controller130and the memory device150may be integrated into a single semiconductor device. For instance, the controller130and the memory device150may be integrated into a semiconductor device configured as a solid state drive (SSD). Configuring the memory system110as a SSD, may generally allow a significant increase in an operation speed of the host102.

The controller130and the memory device150may be integrated into a semiconductor device configured as a memory card, such as a Personal Computer Memory Card International Association (PCMCIA) card, a compact flash (CF) card, a smart media (SM) card (SMC) a memory stick, a multimedia card (MMC), an RS-MMC and a micro-MMC, a secure digital (SD) card, a mini-SD a micro-SD and an SDHC, a universal flash storage (UFS) device and the like.

Also, for example, the memory system110may be or comprise a computer, an ultra-mobile PC (UMPC), a workstation, a net-book, a personal digital assistant (PDA), a portable computer, a web tablet, a tablet computer, a wireless phone, a mobile phone, a smart phone, an e-book, a portable multimedia player (PMP), a portable game player, a navigation device, a black box, a digital camera, a digital multimedia broadcasting (DMB) player, a three-dimensional (3D) television, a smart television, a digital audio recorder, a digital audio player, a digital picture recorder, a digital picture player, a digital video recorder, a digital video player, a storage configuring a data center, a device capable of transmitting and receiving information under a wireless environment, one of various electronic devices configuring a home network, one of various electronic devices configuring a computer network, one of various electronic devices configuring a telematics network, an RFID device, one of various component elements configuring a computing system and the like.

The memory device150may store data provided from the host102. During a read operation, the memory device150may provide the stored data to the host102. One or more memory devices150may be employed. The one or more memory devices150may be substantially identical. The one or more memory devices may be different memory devices. The memory device150may include one or more memory blocks152,154and156. Each of the memory blocks152,154and156may include a plurality of pages. Each of the pages may include a plurality of memory cells coupled electrically to a plurality of word lines (WL). The memory device150may be a nonvolatile memory device capable of retaining stored data even when a power supply is interrupted or turned off. According to an embodiment, the memory device may be a flash memory. The memory device may be a flash memory device having a three-dimensional (3D) stack structure. Examples of a non-volatile memory device150having a three-dimensional (3D) stack structure are described later herein with reference toFIGS. 2 to 11.

The controller130may control the overall operation of the memory device150, such as, read, write, program and/or erase operations. Generally, the controller130may control the memory device150in response to a request from the host102. For example, the controller130may provide data read from the memory device150, to the host102, in response to a read request from the host102. Or, also as an example, the controller may store data provided from the host102into the memory device150in response to a write request.

Any suitable controller may be used. For example, the controller130may include a host interface unit132, a processor134, an error correction code (ECC) unit138, a power management unit (PMU)140, a NAND flash controller (NFC)142, and a memory144.

The host interface unit132may process commands and/or data provided from the host102. The host interface unit132may communicate with the host102through at least one of various interface protocols, such as a universal serial bus (USB), a multimedia card (MMC), a peripheral component interconnect-express (PCI-E), a serial attached SCSI (SAS), a serial advanced technology attachment (SATA), a parallel advanced technology attachment (PATA), a small computer system interface (SCSI), an enhanced small disk interface (ESDI), integrated drive electronics (IDE) and the like. The host interface unit132may include any suitable circuits, systems or devices suitable for communicating with the host102and the other components of the controller130as may be needed.

The ECC unit138may detect and correct errors of the data read from the memory device150during a read operation. Various detection and correction techniques may be employed. For example, if the number of the error bits detected by the ECC unit138is greater than or equal to a threshold number of correctable error bits, the ECC unit138may not correct the error bits and output an error correction fail signal indicating failure in correcting the error bits.

The ECC unit138may perform an error correction operation based on any suitable error correction scheme. For example the ECC unit138may perform an error correction operation based on a coded modulation scheme, such as, for example, a low density parity check (LDPC) code, a Bose-Chaudhuri-Hocquenghem (BCH) code, a turbo code, a Reed-Solomon (RS) code a convolution code, a recursive systematic code (RSC), a trellis-coded modulation (TCM), a Block coded modulation (BCM), and the like. The ECC unit138may include any suitable circuits, systems or devices required for an error detection and correction operation.

The PMU140may provide and manage electric power for the controller130. For example, the PMU140may provide and manage electric power for the various components of the controller130as may be needed.

The NFC142may serve as a memory interface between the controller130and the memory device150to allow the controller130to control the memory device150in response to a request from the host102. For example, the NFC142may generate control signals for the memory device150. The NFC may process data under the control of the processor134, for example, when the memory device150is a flash memory especially a NAND flash memory.

The memory144may serve as a working memory of the memory system110and the controller130, and store data for driving the memory system110and the controller130. For example, when the controller130controls the operations of the memory device150, the memory144may store data used by the controller130and the memory device150for such operations as read, write, program and erase operations.

The memory144may be or comprise a volatile memory. For example, the memory144may be or comprise a static random access memory (SRAM) or a dynamic random access memory (DRAM). As described above, the memory144may store data used by the host102and the memory device150for read and/or write operations. The memory144may be or comprise a program memory, a data memory, a write buffer, a read buffer, a map buffer, and the like.

The processor134may control the general operations of the memory system110. For example the processor134may control a write operation for the memory device150, in response to a write request from the host102. Also, for example, the processor134may control a read operation for the memory device150, in response to a read request from the host102. The processor134may drive a firmware, also referred to as a flash translation layer (FTL), for controlling the general operations of the memory system110. The processor134may be implemented with a microprocessor, a central processing unit (CPU) and the like. Any suitable processor may be used.

For example, a management unit (not shown) may be included in the processor134for performing bad block management of the memory device150. Accordingly, the management unit may find bad memory blocks included in the memory device150, i.e., memory blocks which are in an unsatisfactory condition for further use, and perform a bad block management operation the bad memory blocks. For example, when a flash memory such as a NAND flash memory is employed as the memory device150, a program failure may occur during a write operation due to inherent characteristics of a NAND logic function. During a bad block management, the data of the program-failed memory blocks (e.g., the bad memory blocks) may be programmed into a new memory block. The bad blocks due to a program fail may seriously deteriorate the utilization efficiency of a memory device, especially one having a 3D stack structure and thus negatively affect the reliability of the memory system110.

Referring toFIG. 2the memory device150may include a plurality of memory blocks, for example, zeroth to (N−1)thblocks210to240, where N is a positive integer. Each of the plurality of memory blocks210to240may include a plurality of pages, for example, 2Mnumber of pages (2MPAGES), where M is a positive integer. Each of the plurality of pages may include a plurality of memory cells to which a plurality of word lines may be coupled electrically. It is noted that any number of suitable blocks and pages per block may be employed.

The memory blocks may be single level cell (SLC) memory blocks and/or multi-level cell (MLC) memory blocks, according to the number of bits which may be stored or expressed in each memory cell. An SLC memory block may include a plurality of pages which are implemented with memory cells each of which is capable of storing 1-bit data. An MLC memory block may include a plurality of pages which are implemented with memory cells each of which is capable of storing multi-bit data, for example, two or more-bit data. A MLC memory block including a plurality of pages which are implemented with memory cells each of which is capable of storing 3-bit data may be employed and will be referred to as a triple level cell (TLC) memory block.

Each of the plurality of memory blocks210to240may store data provided from the host device102during a write operation, and may provide stored data to the host102during a read operation.

Referring toFIG. 3, a memory block152of the memory device150may include a plurality of cell strings340coupled electrically to bit lines BL0to BLm−1, respectively. Each cell string340may include at least one drain select transistor DST and at least one source select transistor SST. A plurality of memory cells or a plurality of memory cell transistors MCD to MCn−1 may be coupled electrically in series between the select transistors DST and SST. The respective memory cells MC0to MCn−1 may consist of multi-level cells (MLC) each of which stores data information of a plurality of bits. The memory cells may have any suitable architecture.

InFIG. 3, ‘DSL’ denotes a drain select line ‘SSL’ denotes a source select line, and ‘CSL’ denotes a common source line.

FIG. 3shows, as an example, a memory block152configured by NAND flash memory cells. It is to be noted, however, that the memory block152is not limited to NAND flash memory and may be realized, in other embodiments by NOR flash memory, hybrid flash memory having at least two kinds of memory cells combined, or a NAND flash memory having a controller built in a memory chip. Also, the operational characteristics of a semiconductor device may be applied to not only a flash memory device in which a charge storing layer is configured by conductive floating gates but also to a charge trap flash (CTF) in which a charge storing layer is configured by a dielectric layer.

It is also noted that the memory device150is not limited to a flash memory device only. For example, the memory device150may be a DRAM or a SRAM device.

A voltage generator310of the memory device150may generate word line voltages, for example, a program voltage, a read voltage or a pass voltage, to be supplied to respective word lines according to an operation mode. The voltage generator310may generate voltages to be supplied to bulks, for example, well regions in which the memory cells are formed. The voltage generator310may perform a voltage generating operation under a control of a control circuit (not shown). The voltage generator310may generate a plurality of variable read voltages to generate a plurality of read data. The voltage generator310may select one of the memory blocks or sectors of a memory cell array, select one of the word lines of the selected memory block, and provide the word line voltages to the selected word line and unselected word lines under the control of the control circuit.

A read/write circuit320of the memory device150may be controlled by the control circuit, and may serve as a sense amplifier or a write driver according to an operation mode. During a verification/normal read operation, the read/write circuit320may serve as a sense amplifier for reading data from the memory cell array. Also, during a program operation, the read/write circuit320may serve as a write driver for driving bit lines according to data to be stored in the memory cell array. The read/write circuit320may receive data to be written in the memory cell array, from a buffer (not shown), during the program operation, and may drive the bit Ines according to the inputted data. To this end, the read/write circuit320may include a plurality of page buffers322,324and326respectively corresponding to the columns (or bit lines) or pairs of the columns (or pairs of bit lines). Each of the page buffers322,324and326may include a plurality of latches (not shown).FIG. 4is a block diagram illustrating an example of the plurality of memory blocks152to156of the memory device150, according to an embodiment of the present invention.

As shown inFIG. 4, the memory device150may include a plurality of memory blocks BLK0to BLKN−1. Each of the memory blocks BLK0to BLKN−1 may be realized in a 3D structure or a vertical structure. The respective memory blocks BLK0to BLKN−1 may include a plurality of structures extending in first to third directions, for example, an x-axis direction, a y-axis direction and a z-axis direction.

The respective memory blocks BLK0to BLKN−1 may include a plurality of NAND strings NS extending in the second direction (FIG. 8). The plurality of NAND strings NS may be provided in the first direction and the third direction. Each NAND string NS may be coupled electrically to a bit line BL, at least one source select line SSL, at least one ground select line GSL, a plurality of word lines WL, at least one dummy word line DWL, and a common source line CSL. The respective memory blocks BLK0to BLKN−1 may be coupled electrically to a plurality of bit lines BL, a plurality of source select lines SSL, a plurality of ground select lines GSL, a plurality of word fines WL, a plurality of dummy word lines DWL, and a plurality of common source lines CSL.

FIG. 5is a perspective view of one memory block BLKi of the plurality memory blocks BLK0to BLKN−1 shown inFIG. 4.FIG. 6is a cross-sectional view taken along a line I-I′ of the memory block BLKi shown inFIG. 5.

Referring toFIGS. 5 and 6, memory block BLKi may include a structure extending in the first to third directions.

The memory block may include a substrate5111including a silicon material doped with a first type impurity. For example, the substrate5111may include a silicon material doped with a p-type impurity. The substrate5111may be a p-type well, for example, a pocket p-well. The substrate5111may further include an n-type well surrounding the p-type well. Although, in the embodiment of the present invention, the substrate5111is exemplified as being the p-type silicon, it is to be noted that the substrate5111is not limited to the p-type silicon.

A plurality of doping regions5311to5314extending in the first direction may be provided over the substrate5111. The doping regions are spaced apart at regular intervals in the third direction. The plurality of doping regions5311to5314may contain a second type impurity that is different from that of the impurity used in substrate5111. For example, the plurality of doping regions5311to5314may be doped with an n-type impurity. Although, in the embodiment of the present invention, first to fourth doping regions5311to5314are exemplified as being the n-type, it is noted that they are not limited to the n-type.

In the region over the substrate5111between the first and second doping regions5311and5312, a plurality of dielectric material regions5112extending in the first direction may be spaced apart at regular intervals in the second direction. The dielectric material regions5112may also be separated from the substrate5111by a preset distance in the second direction. Each of the dielectric material regions5112may be separated from one other by a preset distance in the second direction. The dielectric materials5112may include any suitable dielectric material, such as, silicon oxide.

In the regions over the substrate5111between two consecutive doping regions, for example, between doping regions5311and5312, a plurality of pillars5113are spaced apart at regular intervals in the first direction. The plurality of pillars5113extend in the second direction and may pass through the dielectric material regions5112so that they may be coupled electrically with the substrate5111. Each pillar5113may include one or more materials. For example, each pillar5113may include an in inner layer5115and an outer surface layer5114. The surface layer5114may include a doped silicon material doped with an impurity. For example, the surface layer5114may include a silicon material doped with the same or same type impurity as the substrate5111. Although, in the embodiment of the present invention, the surface layer5114is exemplified as including p-type silicon, the surface layer5114is not limited to the p-type silicon and other embodiments may readily envisaged by the skilled person wherein the substrate5111and the surface layer5114of the pillars5113may be doped with an n-type impurity.

The inner layer5115of each pillar5113may be formed of a dielectric material. The inner layer5115may be or include a dielectric material such as silicon oxide.

In the regions between the first and second doping regions5311and5312, a dielectric layer5116may be provided along exposed surfaces of the dielectric material regions5112, the pillars5113and the substrate5111. A thickness of the dielectric layer5116may be less than one half of the distance between the dielectric material regions5112. In other words a region of a material other than the dielectric material5112and the dielectric layer5116may be provided between (i) the dielectric layer5116below the bottom surface of a first dielectric material of the dielectric material regions5112and (ii) the dielectric layer5116provided over the top surface of a second dielectric material of the dielectric material regions5112. The dielectric material regions5112may lie below the first dielectric material.

In the regions between consecutive doping regions such as in the region between the first and second doping regions5311and5312, a plurality of conductive material regions5211to5291may be provided over an exposed surface of the dielectric layer5116. The plurality of the conductive material regions extending in the first direction may be spaced apart at regular intervals in the second direction in an interleaving configuration with the plurality of the dielectric material regions5112. The dielectric layers5116fill the space between the conductive material regions and the dielectric material regions5112. So for example, the conductive material region5211extending in the first direction may be provided between the dielectric material region5112adjacent to the substrate5111and the substrate5111. In particular, the conductive material region5211extending in the first direction may be provided between (i) the dielectric layer5116disposed over the substrate5111and (ii) the dielectric layer5116disposed below the bottom surface of the dielectric material region5112adjacent to the substrate5111.

Each of the conductive material regions5211to5291extending in the first direction may be provided between (i) a dielectric layer5116disposed over the top surface of one of the dielectric material regions5112and (ii) the dielectric layer5116disposed below the bottom surface of the next dielectric material region5112. The conductive material regions5221to5281extending in the first direction may be provided between the dielectric material regions5112. The top conductive material region5291extending in the first direction may be provided over the uppermost dielectric material5112. The conductive material regions5211to5291extending in the first direction may be made of or include a metallic material. The conductive material regions5211to5291extending in the first direction may be made of or include a conductive material such as polysilicon.

In the region between the second doping region5312and third doping region5313, the same structures as the structures between the first and second doping regions5311and5312may be provided. For example, in the region between the second and third doping regions5312and5313, the plurality of dielectric material regions5112extending in the first direction, the plurality of pillars5113which are sequentially arranged in the first direction and pass through the plurality of dielectric material regions5112in the second direction, the dielectric layer5116which is provided over the exposed surfaces of the plurality of dielectric material regions5112and the plurality of pillars5113, and the plurality of conductive material regions5212to5292extending in the first direction may be provided.

In the region between the third doping region5313and a fourth doping region5314, the same structures as between the first and second doping regions5311and5312may be provided. For example, in the region between the third and fourth doping regions5313and5314, the plurality of dielectric material regions5112extending in the first direction, the plurality of pillars5113which are sequentially arranged in the first direction and pass through the plurality of dielectric material regions5112in the second direction, the dielectric layer5116which is provided over the exposed surfaces of the plurality of dielectric material regions5112and the plurality of pillars5113, and the plurality of conductive material regions5213to5293extending in the first direction may be provided.

Drains5320may be respectively provided over the plurality of pillars5113. The drains5320may be made of silicon materials doped with second type impurities. The drains5320may be made of silicon materials doped with n-type impurities. Although for the sake of convenience of explanation, the drains5320are exemplified as including n-type silicon, it is noted that the drains5320are not limited to the n-type silicon. For example, the width of each drain5320may be larger than the width of each corresponding pillar5113. Each drain5320may be provided in the shape of a pad over the top surface of each corresponding pillar5113.

Conductive material regions5331to5333extending in the third direction may be provided over the drains5320. Each of the conductive material regions5331to5333may be extendedly disposed over the drains5320serially arranged in the third direction with a preset separation distance to each other in the first direction. The respective conductive material regions5331to5333may be coupled electrically with the drains5320therebelow. The drains5320and the conductive material regions5331to5333extending in the third direction may be coupled electrically with through contact plugs. The conductive material regions5331to5333extending in the third direction may be made of a metallic material. The conductive material regions5331to5333extending in the third direction may be made of a conductive material such as polysilicon.

InFIGS. 5 and 6, the respective pillars5113may form strings together with the dielectric layer5116and the conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction. The respective pillars5113may form NAND strings NS together with the dielectric layer5116and the conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction. Each NAND string NS may include a plurality of transistor structures TS.

Referring now toFIG. 7, in the transistor structure TS shown inFIG. 6, the dielectric layer5116may include first to third sub dielectric layers5117,5118and5119.

The surface layer5114of p-type silicon in each of the pillars5113may serve as a body. The first sub dielectric layer5117adjacent to the pillar5113may serve as a tunneling dielectric layer, and may include a thermal oxidation layer.

The second sub dielectric layer5118may serve as a charge storing layer. The second sub dielectric layer5118may serve as a charge capturing layer, and may include a nitride layer or a metal oxide layer such as an aluminum oxide layer, a hafnium oxide layer, or the like.

The third sub dielectric layer5119adjacent to the conductive material5233may serve as a blocking dielectric layer. The third sub dielectric layer5119adjacent to the conductive material5233extending in the first direction may be formed as a single layer or multiple layers. The third sub dielectric layer5119may be a high-k dielectric layer such as an aluminum oxide layer, a hafnium oxide layer, or the like, which has a dielectric constant greater than the first and second sub dielectric layers5117and5115.

The conductive material5233may serve as a gate or a control gate. For example, the gate or the control gate5233, the blocking dielectric layer5119, the charge storing layer5118, the tunneling dielectric layer5117and the body5114may form a transistor or a memory cell transistor structure. For example, the first to third sub dielectric layers5117to5119may form an oxide-nitride-oxide (ONO) structure. In the embodiment, for the sake of convenience of explanation, the surface layer5114of p-type silicon in each of the pillars5113will be referred to as a body in the second direction.

The memory block BLKi may include the plurality of pillars5113. For example, the memory block BLKi may include the plurality of NAND strings NS. In detail, the memory block BLKi may include the plurality of NAND strings NS extending in the second direction or a direction perpendicular to the substrate5111.

Each NAND string NS may include the plurality of transistor structures TS which are disposed in the second direction. At least one of the plurality of transistor structures TS of each NAND string NS may serve as a string source transistor SST. At least one of the plurality of transistor structures TS of each NAND string NS may serve as a ground select transistor GST.

The gates or control gates may correspond to the conductive its material regions5211to5291,5212to5292and5213to5293extending in the first direction. For example, the gates or the control gates may extend in the first direction and form word lines and at least two select lines including at least one source select line SSL and at least one ground select line GSL.

The conductive material regions5331to5333extending in the third direction may be coupled electrically to one end of the NAND strings NS. The conductive material regions5331to5333extending in the third direction may serve as bit lines BL. For example, in one memory block BLKi, the plurality of NAND strings NS may be coupled electrically to one-bit line BL.

The second type doping regions5311to5314extending in the first direction may be provided to the other ends of the NAND strings NS. The second type doping regions5311to5314extending in the first direction may serve as common source lines CSL.

For example, the memory block BLKi may include a plurality of NAND strings NS extending in a direction perpendicular to the substrate5111, e.g., the second direction, and may serve as a NAND flash memory block, for example, of a charge capturing type memory, in which the plurality of NAND strings NS are coupled electrically to one-bit line BL.

Although it is illustrated inFIGS. 5 to 7that the conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction are provided by nine (9) layers, it is noted that the conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction are not limited thereto. For example, conductive material regions extending in the first direction may be provided in eight (8) layers, sixteen (16) layers or any multiple layers. For example, in one NAND string NS, the number of transistors may be 8, 16 or more.

Although it is illustrated inFIGS. 5 to 7that three (3) NAND strings NS are coupled electrically to one-bit line BL, it is noted that the embodiment is not limited thereto. In the memory block BLKi, m NAND, strings NS may be coupled electrically to one-bit line BL, m being a positive integer. The number of conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction and the number of common source lines5311to5314may be varied with the number of NAND strings NS which are coupled electrically to one-bit line BL.

Further, although it is illustrated inFIGS. 5 to 7that three (3) NAND strings NS are coupled electrically to one conductive material extending in the first direction, it is noted that the embodiment is not limited thereto. For example, n NAND strings NS may be coupled electrically to one conductive material extending in the first direction, n being a positive integer. The number of bit lines5331to5333may be varied with the number of NAND strings NS which are coupled electrically to one conductive material extending in the first direction.

Referring toFIG. 8, in a block BLKi having the first structure, a plurality of NAND strings NS11to NS31may be provided between a first bit line BL1and a common source line CSL. The first bit line BL1may correspond to the conductive material region5331ofFIGS. 5 and 6, extending in the third direction. NAND strings NS12to NS32may be provided between a second bit line BL2and the common source line CSL. The second bit line BL2may correspond to the conductive material region5332ofFIGS. 5 and 6, extending in the third direction. NAND strings NS13to NS33may be provided between a third bit line BL3and the common source line CSL. The third bit line BL3may correspond to the conductive material region5333ofFIGS. 5 and 6, extending in the third direction.

A source select transistor SST of each NAND string NS may be coupled electrically to a corresponding bit line BL. A ground select transistor GST of each NAND string NS may be coupled electrically to the common source line CSL. Memory cells MC1and MC6may be provided between the source select transistor SST and the ground select transistor GST of each NAND string NS.

In this example, the NAND strings NS may be defined by units of rows and columns. The NAND strings NS which are coupled electrically to one-bit line may form one column. The NAND strings NS11to NS31which are coupled electrically to the first bit line BL1may correspond to a first column. The NAND strings NS12to NS32which are coupled electrically to the second bit line BL2may correspond to a second column. The NAND strings NS13to NS33which are coupled electrically to the third bit line BL3may correspond to a third column. The NAND strings NS which are coupled electrically to one source select line SSL may form one row. The NAND strings NS11to NS13which are coupled electrically to a first source select line SSL1may form a first row. The NAND strings NS21to NS23which are coupled electrically to a second source select line SSL2may form a second row. The NAND strings NS31to NS33which are coupled electrically to a third source select line SSL3may form a third row.

In each NAND string NS, a height may be defined. In each NAND string NS, the height of the memory cell MC1adjacent to the ground select transistor GST may have, for example, a value ‘1’. In each NAND string NS, the height of a memory cell may increase as the memory cell gets closer to the source select transistor SST when measured from the substrate5111. For example, in each NAND string NS, the height of a memory cell MC6adjacent to the source select transistor SST may have, for example, a value ‘7’.

The source select transistors SST of the NAND strings NS arranged in the same row may share the source select line SSL. The source select transistors SST of the NAND strings NS arranged in different rows may be respectively coupled electrically to the different source select lines SSL1, SSL2and SSL3.

The memory cells at the same height in the NAND strings NS in the same row may share a word line WL. For example, at the same height, the word lines WL coupled electrically to the memory cells MC of the NAND strings NS in different rows may be coupled electrically with each other. Dummy memory cells DMC at the same height in the NAND strings NS of the same row may share a dummy word line DWL. For example, at the same height or level, the dummy word lines DWL coupled electrically to the dummy memory cells DMC of the NAND strings NS in different rows may be coupled electrically with each other.

The word lines WL or the dummy word lines DWL located at the same level or height or layer may be coupled electrically with each other for each of the layers where the conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction may be provided. The conductive material regions5211to5291,5212to5292and5213to5293extending in the first direction may be coupled electrically in common to upper layers through contacts. In other words, the ground select transistors GST of the NAND strings NS in the same row may share the ground select line GSL. Further, the ground select transistors GST of the NAND strings NS in different rows may share the ground select line GSL. For example, the NAND strings NS11to NS13, NS21to NS23and NS31to NS33may be coupled electrically in common to the ground select line GSL.

The common source line CSL may be coupled electrically in common to the NAND strings NS. Over the active regions over the substrate5111, the first to fourth doping regions5311to5314may be coupled electrically. The first to fourth doping regions5311to5314may be coupled electrically in common to an upper layer through contacts.

For example, as shown inFIG. 8the word lines WL of the same height or level may be coupled electrically to each other. Accordingly, when a word line WL at a certain height is selected, all NAND strings NS which are coupled electrically to the selected word line WL may be selected. The NAND strings NS in different rows may be coupled electrically to different source select lines SSL. Accordingly, among the NAND strings NS coupled electrically to the same word line WL, by selecting one of the source select lines SSL1to SSL3, the NAND strings NS in the unselected rows may be electrically isolated from the bit lines BL1to BL3. In other words, by selecting one of the source select lines SSL1to SSL3, the NAND strings NS arranged in the same row as the selected source line may be selected. Furthermore, by selecting one of the bit lines BL1to BL3, the NAND strings NS arranged in the same column as the selected bit line may be selected. Accordingly, only the NAND strings NS arranged in the same row as the selected source line and the same column as the selected bit line may be selected.

In each NAND string NS, a dummy memory cell DMC may be provided. InFIG. 8, for example, the dummy memory cell DMC may be provided between a third memory cell MC3and a fourth memory cell MC4in each NAND string NS. For example, first to third memory cells MC1to MC3may be provided between the dummy memory cell DMC and the ground select transistor GST. Fourth to sixth memory cells MC4to MC6may be provided between the dummy memory cell DMC and the source select transistor SST. The memory cells MC of each NAND string NS may be divided into two (2) memory cell groups by the dummy memory cell DMC. In the divided memory cell groups, memory cells, for example, MC1to MC3, adjacent to the ground select transistor GST may be referred to as a lower memory cell group, and remaining memory cells for example, MC4to MC6, adjacent to the string select transistor SST may be referred to as an upper memory cell group.

Herein below, detailed descriptions will be made with reference toFIGS. 9 to 11, which show a memory device in a memory system, according to an embodiment implemented with a three-dimensional (3D) nonvolatile memory device different from the first structure.

FIG. 9is perspective view schematically illustrating a memory device implemented with a three-dimensional (3D) nonvolatile memory device, which is different from the first structure described above with reference toFIGS. 5 to 8and showing a memory block BLKj of the plurality of memory blocks ofFIG. 4.FIG. 10is a cross-sectional view illustrating the memory block BLKj taken along the line VII-VII′ ofFIG. 9.

Referring toFIGS. 9 and 10the memory block BLKj may include structures extending in the first to third directions and may include a substrate6311. The substrate6311may include a silicon material doped with a first type impurity. For example, the substrate6311may include a silicon material doped with a p-type impurity. The substrate6311may be a p-type well, for example, a pocket p-well. The substrate6311may further include an n-type well which surrounds the p-type well. Although, in the described embodiment, the substrate6311is exemplified as being the p-type silicon, it is noted that the substrate6311is not limited to the p-type silicon.

First to fourth conductive material regions6321to6324extending in an x-axis direction and a y-axis direction are provided over the substrate6311. The first to fourth conductive material regions6321to6324may be separated by a preset distance in the z-axis direction.

Fifth to eighth conductive material regions6325to6328extending in the x-axis direction and the y-axis direction may be provided over the substrate6311. The fifth to eighth conductive material regions6325to6328may be separated by the preset distance in the z-axis direction. The fifth to eighth conductive material regions6325to6328may be separated from the first to fourth conductive material regions6321to6324in the y-axis direction.

A plurality of lower pillars DP passing through the first to fourth conductive material regions6321to6324may be provided. Each lower pillar DP may extend in the z-axis direction. Also, a plurality of upper pillars UP passing through the fifth to eighth conductive material regions6325to6328may be provided. Each upper pillar UP may extend in the z-axis direction.

Each of the lower pillars DP and the upper pillars UP may include an internal material6361, an intermediate layer6362, and a surface layer6363. The intermediate layer6362may serve as a channel of the cell transistor. The surface layer6363may include a blocking dielectric layer, a charge storing layer and a tunneling dielectric layer.

The lower and the upper pillars DP and UP may be coupled electrically with each other through a pipe gate PG. The pipe gate PG may be disposed in the substrate6311. For example, the pipe gate PG may include the same material as the lower pillar DP and the upper pillar UP.

A doping material6312of a second type extending in the x-axis direction and the y-axis direction may be provided over the lower pillars DP. For example, the doping material6312of the second type may include an n-type silicon material. The doping material6312of the second type may serve as a common source line CSL.

Drains6340may be provided over the upper pillars UP. The drains6340may include an n-type silicon material. First and second upper conductive material regions6351and6352extending in the y-axis direction may be provided over the drains6340.

The first and second upper conductive material regions6351and6352may be spaced apart along the x-axis direction. The first and second upper conductive material regions6351and6352may be formed of a metal. The first and second upper conductive material regions6351and6352and the drains6340may be coupled electrically with each other through contact plugs. The first and second upper conductive material regions6351and6352may serve as first and second bit lines BL1and BL2, respectively.

The first conductive material6321may serve as a source select line SSL, The second conductive material6322may serve as a first dummy word line DWL1. The third and fourth conductive material regions6323and6324may serve as first and second main word lines MWL1and MWL2, respectively. The fifth and sixth conductive material regions6325and6326may serve as third and fourth main word lines MWL3and MWL4, respectively. The seventh conductive material6327may serve as a second dummy word line DWL2. The eighth conductive material6328may serve as a drain select line DSL.

The lower pillar DP and the first to fourth conductive material regions6321to6324adjacent to the lower pillar DP may form a lower string. The upper pillar UP and the fifth to eighth conductive material regions6325to6328adjacent to the upper pillar UP may form an upper string. The lower string and the upper string may be coupled electrically with each other through the pipe gate PG. One end of the lower string may be coupled electrically to the doping material6312of the second type which serves as the common source line CSL. One end of the upper string may be coupled electrically to a corresponding bit line through the drain6340. One lower string and one upper string may form one cell string which is coupled electrically between the doping material6312serving as the common source line CSL and a corresponding one of the upper conductive material layers6351and6352serving as the bit line BL.

For example, the lower string may include a source select transistor SST, the first dummy memory cell DMC1, and the first and second main memory cells MMC1and MMC2. The upper string may include the third and fourth main memory cells MMC3and MMC4, the second dummy memory cell DMC2, and a drain select transistor DST.

InFIGS. 9 and 10, the upper string and the lower string may form a NAND string NS. The NAND string NS may include a plurality of transistor structures TS. Since the transistor structure included in the NAND string NS inFIGS. 9 and 10is described above in detail with reference toFIG. 7, a detailed description thereof will be omitted herein.

FIG. 11is a circuit diagram illustrating the equivalent circuit of the memory block BLKj having the second structure as described above with reference toFIGS. 9 and 10. For the sake of convenience, only a first string ST1and a second string ST2are shown, forming a pair in the memory block BLKj in the second structure.

Referring toFIG. 11, in the memory block BLKj having the second structure, a plurality of cell strings, each of which is implemented with one upper string and one lower string coupled electrically through the pipe gate PG as described above with reference toFIGS. 9 and 10, may be provided, in such a way as to define a plurality of pairs.

For example, in memory block BLKj having the second structure, memory cells CG0to CG31stacked along a first channel CH1(not shown), for example, at least one source select gate SSG1and at least one drain select gate DSG1may form a first string ST1, and memory cells CG0to CG31stacked along a second channel CH2(not shown), for example at least one source select gate SSG2and at least one drain select gate DSG2may form a second string ST2.

The first and the second strings ST1and ST2may be coupled electrically to the same drain select line DSL and the same source select line SSL. The first string ST1may be coupled electrically to a first bit line BL1. The second string ST2may be coupled electrically to a second bit line BL2.

AlthoughFIG. 11shows the first string ST1and the second string ST2are coupled electrically to the same drain select line DSL and the same source select line SSL, it may be envisaged that the first string ST1and the second string ST2may be coupled electrically to the same source select line SSL and the same bit line BL, the first string ST1may be coupled electrically to a first drain select line DSL1and the second string ST2may be coupled electrically to a second drain select line DSL2. Further it may be envisaged that the first string ST1and the second string ST2may be coupled electrically to the same drain select line DSL and the same bit line BL, the first string ST1may be coupled electrically to a first source select line SSL1and the second string ST2may be coupled electrically a second source select line SSL2.

FIGS. 12A and 12Bare schematic diagrams illustrating command management of the memory system110, in accordance with an embodiment of the present invention.

FIG. 12Aillustrates the memory system110including a plurality of memory devices1501and1502and the controller130.

Each of the memory devices1501and1502may correspond to the memory device150described with reference toFIG. 1.

The controller130may, in addition to the features described earlier, further include a command storage unit1445for storing a plurality of input commands IN_CMD<1:7> received from the host102as a plurality of commands CMD<1:7>. The controller130may control the command storage unit1445to store the plurality of commands CMD<1:7> in a form of a linked-list in which the plurality of commands CMD<1:7> are sequentially linked.

The command storage unit1445may be provided in the memory144of the controller130. However, the command storage unit1445may be included as a separate component, or in another component operatively inked to the memory144.

The controller130may transmit the stored commands CMD<1:7> to the plurality of memory devices1501and1502as commands CMD# for controlling the operations of the respective memory devices1501and1502.

Each of the input commands IN_CMD<1:7> inputted to the command storage unit1445may include ‘priority information’ representing process priority of the corresponding the input commands. That is, when the host102generates the plurality of input commands IN_CMD<1:7>, the host102may include ‘priority information’ in the plurality of input commands IN_CMD<1:7>, in order to designate with which priority the generated commands are to be executed.

The priority information included in each of the input commands IN_CMD<1:7> which are inputted to the command storage unit1445of the controller130from the host102may have the following types.

First, the priority information may include high priority information MUST COMMAND which requests a compulsory change of an execution sequence, regardless of an input order of the input commands are transmitted to the command storage unit1445of the controller130from the host102.

Second, the priority information may include low priority information BEST COMMAND which requests that the input commands are sequentially executed according to the input order of the input commands, while requesting a flexible change of the execution sequence are transmitted to the command storage unit1445of the controller130from the host102.

Specifically, the high priority information MUST COMMAND may include order information O (Order) and head information H (Head). The order information O requesting that the input commands must be executed prior to a command having the low priority information BEST COMMAND, and the head information H requesting that the input commands must be first executed.

Thus, when a command including the order information O is inputted to the command storage unit1445of the controller130from the host102, the command must be inserted ahead of a command having the low priority information BEST COMMAND.

Furthermore, when a command including the head information H is inputted to the command storage unit1445of the controller130from the host102, the command must be inserted the head.

The low priority information BEST COMMAND may include sequential information S (Simple) and flexible information CP (Command Priority). The sequential information S requesting that the input commands are sequentially executed according to the input order of the input commands are transmitted to the command storage unit1445of the controller130from the host102and the flexible information CP requesting the flexible change of the execution sequence such that the input commands are executed prior to a command having the sequential information S.

Thus, when a command having the sequential information S is inputted to the command storage unit1445of the controller130from the host102, the command may be inserted to the tail.

Furthermore, when a command having the flexible information CP is inputted to the command storage unit1445of the controller130from the host102, the command may be inserted as ahead of a command having the sequential information S as possible. However, the flexible information CP has no compulsion, unlike the above-described high-level priority information MUST COMMAND.

That is, the command having the flexible information CP may be inserted behind the command having the sequential information S, according to the condition of the command having the sequential information S, which has been previously inputted.

For example, when it is confirmed that a specific command having the sequential information S, which had been inputted before the point of time that a command having the flexible information CP was inputted, was not executed even after a preset time has elapsed from the point of time that the specific command was inputted, the specific command having the sequential information S may be set to be executed prior to the command having the flexible information CP.

FIG. 12Billustrates how the plurality of input commands IN_CMD<1:7> having the priority information and generated by the host102as illustrated inFIG. 12Aare inputted as the plurality of commands CMD<1:7> to the command storage unit1445of the controller130.

Specifically, the first input command IN_CMD1among the plurality of input commands IN_CMD<1:7> applied to the controller130from the host102may contain the sequential information S as the priority information, and request a read operation R0for the zeroth logical address.

At this time, since the command storage unit1445is empty at the point of time that the first input command IN_CMD1inputted, the first input command IN_CMD1may be stored as the first command CMD1into the head of the command storage unit1445.

The second input command IN_CMD2may contain the flexible information CP as the priority information, and request a write operation W0for the zeroth logical address.

At this time, the first command CMD1having the sequential information S may be stored in the head of the command storage unit1445at the point of time that the second input command IN_CMD2is inputted. Since the second input command IN_CMD2contains the flexible information CP, the first command CMD1which has been stored in the head of the command storage unit1445may be shifted and stored as the second command CMD2, and the second input command IN_CMD2may be stored as the new first command CMD1in the head of the command storage unit1445.

The third input command IN_CMD3may contain the order information O as the priority information, and request a read operation R1for the first logical address.

At this time, the first command CMD1having the flexible information CP and the second command CMD2having the sequential information S may be stored from the head of the command storage unit1445at the point of time that the third input command IN_CMD3is inputted. Since the third input and IN_CMD3contains the order information O, the first and second commands CMD1and CMD2which have been stored from the head of the command storage unit1445may be shifted and stored as the second and third commands CMD2and CMD3, and the third input command IN_CMD3may be stored as the new first command CMD1into the head of the command storage unit1445.

The fourth input command IN_CMD4may contain the sequential information S as the priority information, and request a read operation R2for the second logical address.

At this time, the first command CMD1having the order information O, the second command CMD2having the flexible information CP, and the third command CMD3having the sequential information S may be sequentially stored from the head of the command storage unit1445at the point of time that the fourth input command IN_CMD4is inputted. Since the fourth input command IN_CMD4contains the sequential information S, the fourth input command IN_CMD4may be stored as the fourth command CMD4behind the third command CMD3of the command storage unit1445.

The fifth input command IN_CMD5may contain the head information H as the priority information, and request a read operation R3for the third logical address.

At this time, the first command CMD1having the order information O, the second command CMD2having the flexible information CP, the third command CMD3having the sequential information S, and the fourth command CMD4having the sequential information S may be stored from the head of the command storage unit1445at the point of time that the fifth input command IN_CMD5is inputted. Since the fifth input command IN_CMD5contains the head information H, the first to fourth commands CMD1to CMD4which have been stored from the head of the command storage unit1445may be shifted and stored as the second to fifth commands CMD2to CMD5, and the fifth input command IN_CMD5may be stored as the new first command CMD1into the head of the command storage unit1445.

The sixth input command IN_CMD6may contain the head information H as the priority information, and request a read operation R4for the fourth logical address.

At this time, the first command CMD1having the head information H, the second command CMD2having the order information O, the third command CMD3having the flexible information CP, the fourth command CMD4having the sequential information S and the fifth command CMD5having the sequential information S may be stored from the head of the command storage unit1445at the point of time that the sixth input command IN_CMD6is inputted. Since the sixth input command IN_CMD6contains the head information H, the first to fifth commands CMD1to CMD5which have been stored from the head of the command storage unit1445may be shifted and stored as the second to sixth commands CMD2to CMD6, and the sixth input command IN_CMD5may be stored as the new first command CMD1into the head of the command storage unit1445.

The seventh input command IN_CMD7may contain the order information O as the priority information, and request a read operation R5for the fifth logical address.

At this time, the first command CMD1having the head information H, the second command CMD2having the head information H, the third command CMD3having the order information O, the fourth command CMD4having the flexible information CP, the fifth command CMD5having the sequential information S, and the sixth command CMD6having the sequential information S may be stored from the head of the command storage unit1445at the point of time that the seventh input command IN_CMD7is inputted. Since the seventh input command IN_CMD7contains the order information O, the fourth to sixth commands CMD4to CMD6which have been stored in the middle of the command storage unit1445may be shifted and stored as the fifth to seventh commands CMD5to CMD7, and the seventh input command IN_CMD7may be stored as the new fourth command CMD4ahead of the fifth command CMD5in the command storage unit1445.

As described above, the sequence in which the plurality of input commands applied from the host102are inputted to the command storage unit1445of the controller130may be varied according to the priority information contained in each of the input commands IN_CMD<1:7>.

FIGS. 13A and 13Bare schematic diagrams illustrating a command management system and method of the memory system110in accordance with another embodiment of the present invention.

The memory system110shown inFIG. 13Amay be the same as the memory system110described with reference toFIG. 12Aexcept for first and second command storage units1441and1442.

Each of the memory devices1501and1502may correspond to the memory device150described with reference toFIG. 4.

The controller130may be configured in the same manner as the controller130described with reference toFIG. 1. At this time, the plurality of input commands IN_CMD<1:7> applied from the host102may be distributed and stored into first and second command storage units1441and1442included in the controller130.

The controller130may select commands having a higher priority than a preset level among the plurality of input commands IN_CMD<1:7> applied from the host102, and store the selected commands in the first command storage unit1441. At this time, the controller130may manage the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4stored in the first command storage unit1441in the form of a linked-list in which the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4are sequentially linked and managed from the head HEAD1to the tail TAIL1.

Furthermore, the controller130may select commands having a lower priority than the preset level among the plurality of input commands IN_CMD<1:7> applied from the host102, and store the selected commands in the second command storage unit1442. At this time, the controller130may manage the commands CMD2/1, CMD2/2, and CMD2/3stored in the second command storage unit1442in the form of a tree-list from the head HEAD2to the tail TAIL2.

The first and second command storage units1441and1442may be positioned in the memory144of the controller130, but may also included as a separate component, or in another component operatively linked to the memory144.

The controller130may distribute and store the plurality of input commands IN_CMD<1:7> applied form the host102into the first and second command storage units1441and1442, and transmit the stored commands CMD1/1, CMD1/2, CMD1/3and CMD1/4and CMD2/1, CMD2/2, and CMD2/3to the plurality of memory devices1501and1502as commands CMD# in order to control the operations of the memory devices1501and1502. That is, each of the memory devices1501and1502may be controlled in response to a command CMD# received from the first or second command storage unit1441or1442through the controller130.

At this time, since the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4having a higher priority than the preset level are stored in the first command storage unit1441and the commands CMD2/1, CMD2/2and CMD2/3having a lower priority than the preset level are stored in the second command storage unit1442, the controller130may control the commands such that the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4stored in the first command storage unit1441can be transmitted to the memory devices1501and1502prior to the commands CMD2/1, CMD2/2, and CMD2/3stored in the second command storage unit1442. For example, the controller130may confirm that no commands are stored in the first command storage unit1441, and then transmit the commands stored in the second command storage unit1442to the memory devices1501and1502.

Each of the input commands IN_CMD<1:7> which are distributed and inputted to the first and second command storage units1441and1442of the controller130from the host102may include ‘priority information’. That is, when the host102generates the plurality of input commands IN_CMD<1:7>, the host102may include the priority information in the plurality of input commands IN_CMD<1:7>, in order to designate with which priority the generated commands are to be executed.

The priority information included in each of the input commands IN_CMD<1:7> which are distributed and inputted to the first and second command storage units1441and1442of the controller130from the host102may have the following types.

First, the priority information may include high priority information MUST COMMAND which requests a compulsory change of an execution sequence, regardless of an input order of the input commands are transmitted to the command storage unit1445of the controller130from the host102. At this time, the controller130may check the priority information of the input commands IN_CMD<1:7> inputted to the controller130from the host102, and input commands having the high priority information MUST COMMAND only to the first command storage unit1441.

Second, the priority information may include low priority information BEST COMMAND which requests that the input commands are sequentially executed according to the input order of the input commands, while requesting a flexible change of the execution sequence are transmitted to the command storage unit1445of the controller130from the host102. At this time, the controller130may check the priority information of the input commands IN_CMD<1:7> inputted to the controller130from the host102, and input commands having the low priority information BEST COMMAND only to the second command storage unit1442.

Specifically, the high priority information MUST COMMAND may include order information O (Order) and head information H (Head). The order information O requesting that the input commands must be executed prior to a command having the low priority information BEST COMMAND, and the head information H requesting that the input commands must be first executed.

Thus, in order that a command having the order information O can be unconditionally executed prior to a command having the low priority information BEST COMMAND, the controller130may input the command having the order information O to the first command storage unit1441.

Furthermore, in order that a command having the head information H can be unconditionally executed at the head, the controller130not only may input the command having the head information H to the first command storage unit1441, but also must insert the command having the head information H to the head HEAD1of the first command storage unit1441.

At this time, the controller130may use a control method that always transmits the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4stored in the first command storage unit1441to the memory devices1501and1502, prior to the commands CMD2/1, CMD2/2, and CMD2/3stored in the second command storage unit1442.

Thus, through the operation of simply inputting the command having the order information O and the command having the head information H to the first command storage unit1441, the command having the order information O can be unconditionally executed prior to a command having the low priority information BEST COMMAND.

The low priority information BEST COMMAND may include sequential information S and flexible information CP. The sequential information S requesting that the input commands are sequentially executed according to the input order of the input commands are transmitted to the controller130from the host102, and the flexible information CP requesting the flexible change of the execution sequence such that the input commands are executed prior its to a command having the sequential information S.

Thus, in order that a command having the sequential information S can be sequentially executed according to the point of time that the command is inputted, the controller130may not only input the command having the sequential information S to the second command storage unit1442, but also insert the command to the tail TAIL2of the second command storage unit1442.

Furthermore, in order that a command having the flexible information CP can be executed as prior to a command having the sequential information S as possible, the controller130may not only input the command having the flexible information CP to the second command storage unit1442, but also insert the command to the head HEAD2of the second command storage unit1442.

At this time, when the command having the flexible information CP is executed as prior to the command having the sequential information S as possible, it may indicate that the command having the flexible information CP can be inserted behind a command having the sequential information S according to the situation of the command having the sequential information S, which has been previously inputted.

For example, when it is confirmed that a specific command having the sequential information S, which had been inputted before the point of time that a command having the flexible information CP was inputted, was not executed even after a preset time has elapsed from the point of time that the command was inputted, the specific command having the sequential information S may be set to be executed prior to the command having the flexible information CP.

FIG. 13Billustrates how the plurality of input commands IN_CMD<1:7> having the flexible information and generated by the host102as illustrated inFIG. 13Aare inputted to the first and second command storage unit1441and1442of the controller130.

First, the plurality of input commands IN_CMD<1:7> may be sequentially applied as new commands INPUT COMMAND to the controller130from the host102.

Specifically, the first input command IN_CMD1among the plurality of input commands IN_CMD<1:7> applied to the controller130from the host102may contain the sequential information S as the priority information, and request a read operation R0for the zeroth logical address.

Since the first input command IN_CMD1contains the sequential information S, the first input command IN_CMD1must be inputted to the second command storage unit1442. At this time, since the second command storage unit1442is empty at the point of time that the first input command IN_CMD1is inputted, the first input command IN_CMD1may be stored as the second-first command CMD2/1in the head HEAD2of the second command storage unit1442.

The second input command IN_CMD2may contain the flexible information CP as the priority information, and request a write operation W0for the zeroth logical address.

Since the second input command IN_CMD2contains the flexible information CP, the second input command IN_CMD2must be inputted to the second command storage unit1442. At this time, the second-first command CMD2/1having the sequential information S is stored in the head HEAD2of the second command storage unit1442at the point of time that the second input command IN_CMD2is inputted. Thus, the second-first command CMD2/1which has been stored in the head HEAD2of the second command storage unit1442may be shifted and stored as the second-second command CMD2/2, and the second input command IN_CMD2may be stored as the new second-first command CMD2/1in the head HEAD2of the second command storage unit1442.

The third input command IN_CMD3may contain the order information O as the priority information, and request a read operation R1for the first logical address.

Since the third input command IN_CMD3contains the order information O, the third input command IN_CMD3must be inputted to the first command storage unit1441. At this time, since the first command storage unit1441is empty at the point of time that the third input command IN_CMD3is inputted, the third input command IN_CMD3may be stored as the first-first command CMD1/1in the head HEAD1of the first command storage unit1441.

The fourth input command IN_CMD4may contain the sequential information S as the priority information, and request a read operation R2for the second logical address.

Since the fourth input command IN_CMD4contains the sequential information S, the fourth input command IN_CMD4must be inputted to the second command storage, unit1442. At this time, the second-first command CMD2/1having the flexible information CP and the second-second command CMD2/2having the sequential information S are stored from the head HEAD2of the second command storage unit1442at the point of time that the fourth input command IN_CMD4is inputted. Thus, the fourth input command IN_CMD4may be stored as the second-third command CMD2/3behind the second-second command CMD2/2in the second command storage unit1442.

The fifth input command IN_CMD5may contain the head information H as the priority information, and request a read operation R3for the third logical address.

Since the fifth input command IN_CMD5contains the head information H, the fifth input command IN_CMD5must be inputted to the first command storage unit1441. At this time, the first-first command CMD1/1having the order information O is stored in the head HEAD1of the first command storage unit1441at the point of time that the fifth input command IN_CMD5is inputted. Thus, the first-first command CMD1/1which has been stored in the head HEAD1of the first command storage unit1441may be shifted and stored as the first-second command CMD1/2, and the fifth input command IN_CMD5may be stored as the new first-first command CMD1/1in the head HEAD1of the first command storage unit1441.

The sixth input command IN_CMD6may contain the head information H as the priority information, and request a read operation R4for the fourth logical address.

Since the sixth input command IN_CMD6contains the head information H, the sixth input command IN_CMD6must be inputted to the first command storage unit1441. At this time, the first-first command CMD1/1having the head information H and the first-second command CMD1/2having the order information O are stored from the head HEAD1of the first command storage unit1441at the point of time that the sixth input command IN_CMD6is inputted. Thus, the first-first command CMD1/1and the first-second command CMD1/2which have been stored from the head HEAD1of the first command storage unit1441may be shifted and stored as the first-second command CMD1/2and the first-third command CMD1/3, and the sixth input command IN_CMD6may be stored as the new first-first command CMD1/1in the head HEAD1of the first command storage unit1441.

The seventh input command IN_CMD7may contain the order information O as the priority information, and request a read operation R5for the fifth logical address.

Since the seventh input command IN_CMD7contains the order information O, the seventh input command IN_CMD7must be inputted to the first command storage unit1441. At this time, the first-first command CMD1/1having the head information H, the first-second command CMD1/2having the head information H, and the first-third command CMD1/3having the order information O are stored from the head HEAD1of the first command storage unit1441at the point of time that the seventh input command IN_CMD7is inputted. Thus, the first-first command CMD1/1the first-second command CMD1/2, and the first-third command CMD1/3which have been stored from the head HEAD1of the first command storage unit1441may not be shifted, but the seventh input command IN_CMD7may be stored as the first-fourth command CMD1/4in the tail TAIL1of the first command storage unit1441.

As described above, the sequence in which the plurality of input commands IN_CMD<1:7> applied from the host102are inputted to the first and second command storage units1441and1442may be varied according to the priority information contained in each of the input commands IN_CMD<1:7>.

In particular, the operation of distributing and storing the plurality of input commands CMD<1:7> applied from the host102into the first and second command storage units1441and1442according to the preset priority inFIGS. 13A and 13Bcan manage the plurality of input commands CMD<1:7> more simply than the operation of inputting the plurality of input commands CMD<1:7> to one command storage unit1445at a time.

For example, during the operation of inputting the plurality of input commands CMD<1:7> applied from the host102to the command storage unit1445at a time as illustrated inFIGS. 12A and 12B, the storage sequence of the commands having the priority information flexible information CP or the sequential information S must be shifted whenever a command having the head information H or the order information O which requests a compulsory change of the sequence is inputted from the host102.

However, during the operation of distributing and storing the plurality of input commands CMD<1:7> applied from the host102into the first and second command storage units1441and1442according to the preset priority illustrated inFIGS. 13A and 13B, a command having the head information H or the order information O (which requires a compulsory change of the sequence) may be stored only in the first command storage unit1441, and a command having the flexible information CP or the sequential information S may be stored only in the second command storage unit1442. Thus, the frequency that the storage sequence is changed can be reduced significantly, compared to the method described with reference toFIGS. 12A and 12B.

Therefore, the method described with reference toFIGS. 13A and 13Bmay process commands even more efficiently than the method described with reference toFIGS. 12A and 12B.

A reason why the controller130manages the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4stored in the first command storage unit1441in the form of a linked-list as described with reference toFIG. 13Amay be that the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4stored in the first, command storage unit1441contain the head information H or the order information O. In other words, the commands CMD1/1, CMD1/2, CMD1/3, and CMD1/4stored in the first command storage unit1441from the head HEAD1to the tail TAIL1may be already aligned through the compulsory sequence change based on the flexible information. Thus, the controller130may need to manage the commands in the form of a linked-list, so that the commands can be executed according to the sequence in which the commands are stored in the first command storage unit1441.

On the other hand, a reason why the controller130manages the commands CMD2/1, CMD2/2and CMD2/3stored in the second command storage units1442in the form of a tree-list may be that the commands CMD2/1, CMD2/2, and CMD2/3stored in the second command storage unit1442contain the flexible information CP or the sequential information S. In other words, since the commands CMD2/1, CMD2/2, and CMD2/3stored in the second command storage unit1442from the head HEAD2to the tail TAIL2are primarily aligned according to the flexible information but not forced to be aligned, the commands CMD2/1, CMD2/2, and CMD2/3can be realigned as may be needed. Thus, the controller130may need to manage the commands stored in the second command storage unit1442in the form of a tree-list, so that the commands are basically executed according to the sequence in which the commands are stored in the second command storage unit1442but can be flexibly managed as may be needed.

Specifically, the case in which the controller130manages the commands CMD2/1, CMD2/2, and CMD2/3stored in the second command storage unit1442in the form of a tree-list will now be described as an example.

First, the controller130may manage commands having the sequential information S, among commands inputted to the second command storage unit1442, at a lower tree level than commands having the flexible information CP. In this case, the commands having the flexible information CP may be executed as prior to the commands having the sequential information S as possible.

The controller130may manage the tree-list levels among the commands having the sequential information S in the second command storage unit1442, based on the logical address values corresponding to the respective commands of the sequential information S. That is, when a plurality of commands having the sequential information S exist, the controller130may properly manage the tree-list levels among the commands having the sequential information S, and determine the execution sequence thereof. At this time, the controller130may align the tree-list levels based on the sequence in which the plurality of commands having the sequential information S are inputted. However, the controller130may align the tree-list levels based on the logical address values corresponding to the plurality of commands having the sequential information S, respectively.

Furthermore, the controller130may manage the tree-list levels among the commands having the flexible information CP in the second command storage unit1442, based on the logical address values corresponding to the respective commands of the flexible information CP. That is, when a plurality of commands having the flexible information CP exist, the controller130may properly manage the tree-list levels among the commands having the flexible information CP, and determine their execution sequence. At this time, the controller130may align the tree-list levels based on the sequence in which the plurality of commands having the flexible information CP are inputted. However, the controller130may align the tree-list levels based on the logical address values corresponding to the plurality of commands having the flexible information CP, respectively.

When a specific command among the commands having the sequential information S in the second command storage unit1442has not been executed for a long time but is ignored as it is, the execution time of the specific command may be excessively delayed. In this case, the host102may determine that an error occurred. Thus, among the commands having the sequential information S in the second command storage unit1442, the execution sequence of a command which is not executed even after lapse of a preset time needs to be controlled, so that the command is executed prior to a command having the flexible information P. Thus, the controller130can transfer the command which is not executed within the preset time after being inputted to the second command storage unit1442, among the commands having the sequential information S in the second command storage unit1442, to a shallower tree-list level than the commands having the flexible information CP, in order to manage the command. For example, when the command of the sequential information S has been stored in the second command storage unit1442over a predetermined time, the command of the sequential information S may be set to have the higher priority to the command of the flexible information CP input to the memory system110after a lapse of the predetermined time.

In accordance with an embodiment of the present invention, the memory system may check the priorities of the plurality of commands inputted from the host, and input commands having a lower priority than a preset level and commands having a higher priority than the preset level to two different commands queues according to the check result, in order to manage the commands.

Through this operation, the two command queues can be processed more simply, thus improving the command processing speed of the memory system.

For example, the positions and types of the logic gates and transistors used in the above-described embodiments may be set in different manners according to the polarities of input signals.