The present disclosure generally relates to the field of electronics. More particularly, aspects generally relate to read operations in memory devices.
Solid state drives (SSDs) or nonvolatile direct in-line memory modules (NV-DIMMs) provide high speed, nonvolatile memory capacity without the need for moving parts. SSDs rely on concurrency in read and write operations to increase performance. Memory in a SSD commonly comprises multiple physically separate “dies” that can be read from in parallel to improve performance. As manufacturers move to increasingly larger die sizes, smaller SSDs require fewer dies in them for a given memory density. This reduces the ability to utilize concurrency to improve read performance. This has a negative effect on performance. Accordingly, techniques to manage read operations in memory devices may find utility, e.g., in memory systems for electronic devices.
The detailed description is provided with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of various examples. However, various examples may be practiced without the specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the particular examples. Further, various aspects of examples may be performed using various means, such as integrated semiconductor circuits (“hardware”), computer-readable instructions organized into one or more programs (“software”), or some combination of hardware and software. For the purposes of this disclosure reference to “logic” shall mean either hardware, software, or some combination thereof.
As described in detail below, by adroitly combining read operation in a read queue read operations directed to different planes on a single die may executed concurrently, thereby increasing performance parameters of a SSD. Specific details of a systems and methods to manage read devices in electronic devices will be described below with reference to
Memory interface 124 is coupled to one or more remote memory devices 140 by a communication bus 160. Storage device 140 may be implemented as a solid state drive (SSD), a nonvolatile direct in-line memory module (NV-DIMM) or the like and comprise a controller 142 and memory 150. In various examples, at least some of the memory 150 may comprise nonvolatile memory, e.g., NAND (flash) memory, ferroelectric random-access memory (FeTRAM), nanowire-based non-volatile memory, memory that incorporates memristor technology, a static random access memory (SRAM), three dimensional (3D) cross point memory, phase change memory (PCM), spin-transfer torque memory (STT-RAM) or NAND memory or NOR memory. The specific configuration of the memory 150 in the memory device(s) 140 is not critical. In such embodiments the memory interface may comprise a Serial ATA interface, a PCI Express (PCIE) to 100 interface, or the like.
Controller 142 may comprise logic, at least partially including hardware logic, defining a multi-plane read module 146. Further, controller 142 may maintain a logical address to physical address mapping table 148 which maps a logical address received with a read request to a physical address in the nonvolatile memory and one or more NAND media channels 248, which are coupled to memory 150 via communication link 144
Operations implemented by controller 142 will be described with reference to
Referring to
At operation 420 the controller 142 determines a target die and a target plane for read operations received from the host device. For example, read operations may arrive from the host device with a logical memory address assigned by the host device. The controller 142 may reference the logical memory address in the logical to physical mapping table 148 to obtain a physical address in the memory 150 from which data in the read operation is to be retrieved. The die and plane information may be associated with the physical address in the read queue. Thus, referring to
At operation 425 the controller 142 scans the read queue 310 for read requests that are directed to the same target die but to different planes on the target die. If, at operation 430 there are no matches then control passes to operation 440 and the controller 142 executes read operations in accordance with normal operations, e.g., the read operations may be executed in a first-in, first-out (FIFO) manner.
By contrast, if at operation 430 there are matches, then control passes to operation 435 and the controller 142 combines matching read requests to form a combined read request. For example, referring to
The controller 142 must allow commands with four fully independent physical address fields (one for each plane) in order to permit multi plane reads to be sent to memory 150. In some examples controller 142 may enable a multiplane read mode in which the plane 2/3/4 transfer buffer destination address fields are used for the plane 2/3/4 page address.
At operation 520 the controller returns data associated with the first read request to the host which generated the first read request, and at operation 525 the controller 142 returns the second data associated with the second read request to a host which generated the second read request. One skilled in the art will recognize that in cases where more than two read requests are combined to form a combined read request the controller may return third data associated with a third read request and/or fourth data associated with a fourth read request.
Some existing controllers such as controller 142 may be limited to using a single same page address for each plane due to a matching limitation in the NAND media. In order to accommodate this limitation, an independent multi-plane read mode may be added to the NAND Media Channel (NMC) block. As described above, in some examples a multi-plane read mode may use the plane 2/3/4 transfer buffer destination address fields to use for the plane 2/3/4 page address.
As described above, in some examples the electronic device may be embodied as a computer system.
A chipset 606 may also communicate with the interconnection network 604. The chipset 606 may include a memory control hub (MCH) 608. The MCH 608 may include a memory controller 610 that communicates with a memory 612 (which may be the same or similar to the memory 130 of
The MCH 608 may also include a graphics interface 614 that communicates with a display device 616. In one example, the graphics interface 614 may communicate with the display device 616 via an accelerated graphics port (AGP). In an example, the display 616 (such as a flat panel display) may communicate with the graphics interface 614 through, for example, a signal converter that translates a digital representation of an image stored in a storage device such as video memory or system memory into display signals that are interpreted and displayed by the display 616. The display signals produced by the display device may pass through various control devices before being interpreted by and subsequently displayed on the display 616.
A hub interface 618 may allow the MCH 608 and an input/output control hub (ICH) 620 to communicate. The ICH 620 may provide an interface to I/O device(s) that communicate with the computing system 600. The ICH 620 may communicate with a bus 622 through a peripheral bridge (or controller) 624, such as a peripheral component interconnect (PCI) bridge, a universal serial bus (USB) controller, or other types of peripheral bridges or controllers. The bridge 624 may provide a data path between the CPU 602 and peripheral devices. Other types of topologies may be utilized. Also, multiple buses may communicate with the ICH 620, e.g., through multiple bridges or controllers. Moreover, other peripherals in communication with the ICH 620 may include, in various examples, integrated drive electronics (IDE) or small computer system interface (SCSI) hard drive(s), USB port(s), a keyboard, a mouse, parallel port(s), serial port(s), floppy disk drive(s), digital output support (e.g., digital video interface (DVI)), or other devices.
The bus 622 may communicate with an audio device 626, one or more disk drive(s) 628, and a network interface device 630 (which is in communication with the computer network 603). Other devices may communicate via the bus 622. Also, various components (such as the network interface device 630) may communicate with the MCH 608 in some examples. In addition, the processor 602 and one or more other components discussed herein may be combined to form a single chip (e.g., to provide a System on Chip (SOC)). Furthermore, the graphics accelerator 616 may be included within the MCH 608 in other examples.
Furthermore, the computing system 600 may include volatile and/or nonvolatile memory (or storage). For example, nonvolatile memory may include one or more of the following: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), a disk drive (e.g., 628), a floppy disk, a compact disk ROM (CD-ROM), a digital versatile disk (DVD), flash memory, a magneto-optical disk, or other types of nonvolatile machine-readable media that are capable of storing electronic data (e.g., including instructions).
In an example, the processor 702-1 may include one or more processor cores 706-1 through 706-M (referred to herein as “cores 706” or more generally as “core 706”), a shared cache 708, a router 710, and/or a processor control logic or unit 720. The processor cores 706 may be implemented on a single integrated circuit (IC) chip. Moreover, the chip may include one or more shared and/or private caches (such as cache 708), buses or interconnections (such as a bus or interconnection network 712), memory controllers, or other components.
In one example, the router 710 may be used to communicate between various components of the processor 702-1 and/or system 700. Moreover, the processor 702-1 may include more than one router 710. Furthermore, the multitude of routers 710 may be in communication to enable data routing between various components inside or outside of the processor 702-1.
The shared cache 708 may store data (e.g., including instructions) that are utilized by one or more components of the processor 702-1, such as the cores 706. For example, the shared cache 708 may locally cache data stored in a memory 714 for faster access by components of the processor 702. In an example, the cache 708 may include a mid-level cache (such as a level 2 (L2), a level 3 (L3), a level 4 (L4), or other levels of cache), a last level cache (LLC), and/or combinations thereof. Moreover, various components of the processor 702-1 may communicate with the shared cache 708 directly, through a bus (e.g., the bus 712), and/or a memory controller or hub. As shown in
As illustrated in
Additionally, the core 706 may include a schedule unit 806. The schedule unit 806 may perform various operations associated with storing decoded instructions (e.g., received from the decode unit 804) until the instructions are ready for dispatch, e.g., until all source values of a decoded instruction become available. In one example, the schedule unit 806 may schedule and/or issue (or dispatch) decoded instructions to an execution unit 808 for execution. The execution unit 808 may execute the dispatched instructions after they are decoded (e.g., by the decode unit 804) and dispatched (e.g., by the schedule unit 806). In an example, the execution unit 808 may include more than one execution unit. The execution unit 808 may also perform various arithmetic operations such as addition, subtraction, multiplication, and/or division, and may include one or more an arithmetic logic units (ALUs). In an example, a co-processor (not shown) may perform various arithmetic operations in conjunction with the execution unit 808.
Further, the execution unit 808 may execute instructions out-of-order. Hence, the processor core 706 may be an out-of-order processor core in one example. The core 706 may also include a retirement unit 810. The retirement unit 810 may retire executed instructions after they are committed. In an example, retirement of the executed instructions may result in processor state being committed from the execution of the instructions, physical registers used by the instructions being de-allocated, etc.
The core 706 may also include a bus unit 714 to enable communication between components of the processor core 706 and other components (such as the components discussed with reference to
Furthermore, even though
In some examples, one or more of the components discussed herein can be embodied as a System On Chip (SOC) device.
As illustrated in
The I/O interface 940 may be coupled to one or more I/O devices 970, e.g., via an interconnect and/or bus such as discussed herein with reference to other figures. I/O device(s) 970 may include one or more of a keyboard, a mouse, a touchpad, a display, an image/video capture device (such as a camera or camcorder/video recorder), a touch screen, a speaker, or the like.
As illustrated in
In an example, the processors 1002 and 1004 may be one of the processors 702 discussed with reference to
As shown in
The chipset 1020 may communicate with a bus 1040 using a point-to-point PtP interface circuit 1041. The bus 1040 may have one or more devices that communicate with it, such as a bus bridge 1042 and I/O devices 1043. Via a bus 1044, the bus bridge 1043 may communicate with other devices such as a keyboard/mouse 1045, communication devices 1046 (such as modems, network interface devices, or other communication devices that may communicate with the computer network 803), audio I/O device, and/or a data storage device 1048. The data storage device 1048 (which may be a hard disk drive or a NAND flash based solid state drive) may store code 1049 that may be executed by the processors 1002 and/or 1004.
The following pertains to further examples.
Example 1 is an electronic device comprising at least one processor, at least one storage device comprising a nonvolatile memory, and a controller coupled to the memory and comprising logic, at least partially including hardware logic, to receive a first read request from a host device, place the first read request in a read queue comprising a plurality of read requests directed to the nonvolatile memory, determine a first target die and a first target plane in the nonvolatile memory for the first read request, and combine the first read request with at least a second read request in the read queue to form a combined read request, wherein the second read request comprises a second target die, which is the same as the first target die, and a second target plane which is different from the first target plane.
In Example 2, the subject matter of Example 1 can optionally include logic, at least partially including hardware logic, to execute the combined read request to retrieve data from the nonvolatile memory requested in the combined read request.
In Example 3, the subject matter of any one of Examples 1-2 can optionally include logic, at least partially including hardware logic, to separate the data retrieved from the combined read request into to first data associated with the first read request and second data associated with the second read request
In Example 4, the subject matter of any one of Examples 1-3 can optionally include logic, at least partially including hardware logic, to return the first data associated with the first read request to a host which generated the first read request and return the second data associated with the second read request to a host which generated the second read request.
In Example 5, the subject matter of any one of Examples 1-4 can optionally include logic, at least partially including hardware logic, to combine the first read request and the second read request in the read queue with at least a third read request in the read queue.
In Example 6, the subject matter of any one of Examples 1-5 can optionally include logic, at least partially including hardware logic, to maintain a logical address to physical address mapping table which maps a logical address received with a read request to a physical address in the nonvolatile memory.
In Example 7, the subject matter of any one of Examples 1-6 can optionally include an arrangement in which one or more physical addresses in the nonvolatile memory are associated with a die and a plane in the nonvolatile memory.
Example 8 is a storage device, comprising a nonvolatile memory, and a controller coupled to the memory and comprising logic, at least partially including hardware logic, to receive a first read request from a host device, place the first read request in a read queue comprising a plurality of read requests directed to the nonvolatile memory, determine a first target die and a first target plane in the nonvolatile memory for the first read request, and combine the first read request with at least a second read request in the read queue to form a combined read request, wherein the second read request comprises a second target die, which is the same as the first target die, and a second target plane which is different from the first target plane.
In Example 9, the subject matter of Example 8 can optionally include logic, at least partially including hardware logic, to execute the combined read request to retrieve data from the nonvolatile memory requested in the combined read request.
In Example 10, the subject matter of any one of Examples 8-9 can optionally include logic, at least partially including hardware logic, to separate the data retrieved from the combined read request into to first data associated with the first read request and second data associated with the second read request
In Example 11, the subject matter of any one of Examples 8-10 can optionally include logic, at least partially including hardware logic, to return the first data associated with the first read request to a host which generated the first read request and return the second data associated with the second read request to a host which generated the second read request.
In Example 12, the subject matter of any one of Examples 8-11 can optionally include logic, at least partially including hardware logic, to combine the first read request and the second read request in the read queue with at least a third read request in the read queue.
In Example 13, the subject matter of any one of Examples 8-12 can optionally include logic, at least partially including hardware logic, to maintain a logical address to physical address mapping table which maps a logical address received with a read request to a physical address in the nonvolatile memory.
In Example 14, the subject matter of any one of Examples 8-13 can optionally include an arrangement in which one or more physical addresses in the nonvolatile memory are associated with a die and a plane in the nonvolatile memory.
Example 15 is a controller coupled to the memory and comprising logic, at least partially including hardware logic, to receive a first read request from a host device, place the first read request in a read queue comprising a plurality of read requests directed to the nonvolatile memory, determine a first target die and a first target plane in the nonvolatile memory for the first read request, and combine the first read request with at least a second read request in the read queue to form a combined read request, wherein the second read request comprises a second target die, which is the same as the first target die, and a second target plane which is different from the first target plane.
In Example 16, the subject matter of Example 15 can optionally include logic, at least partially including hardware logic, to execute the combined read request to retrieve data from the nonvolatile memory requested in the combined read request.
In Example 17, the subject matter of any one of Examples 15-16 can optionally include logic, at least partially including hardware logic, to separate the data retrieved from the combined read request into to first data associated with the first read request and second data associated with the second read request
In Example 18, the subject matter of any one of Examples 15-17 can optionally include logic, at least partially including hardware logic, to return the first data associated with the first read request to a host which generated the first read request and return the second data associated with the second read request to a host which generated the second read request.
In Example 19, the subject matter of any one of Examples 15-18 can optionally include logic, at least partially including hardware logic, to combine the first read request and the second read request in the read queue with at least a third read request in the read queue.
In Example 20, the subject matter of any one of Examples 15-19 can optionally include logic, at least partially including hardware logic, to maintain a logical address to physical address mapping table which maps a logical address received with a read request to a physical address in the nonvolatile memory.
In Example 21, the subject matter of any one of Examples 15-20 can optionally include an arrangement in which one or more physical addresses in the nonvolatile memory are associated with a die and a plane in the nonvolatile memory.
In various examples, the operations discussed herein, e.g., with reference to
Reference in the specification to “one example” or “an example” means that a particular feature, structure, or characteristic described in connection with the example may be included in at least an implementation. The appearances of the phrase “in one example” in various places in the specification may or may not be all referring to the same example.
Also, in the description and claims, the terms “coupled” and “connected,” along with their derivatives, may be used. In some examples, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements may not be in direct contact with each other, but may still cooperate or interact with each other.
Thus, although examples have been described in language specific to structural features and/or methodological acts, it is to be understood that claimed subject matter may not be limited to the specific features or acts described. Rather, the specific features and acts are disclosed as sample forms of implementing the claimed subject matter.