The present disclosure generally relates to the field of electronics. More particularly, some embodiments of the invention generally relate to memory.
Volatile memory technology such as Dynamic Random Access Memory (DRAM) technologies for example, JEDEC standard DRAM such as Dual Data Rate-3 (DDR3), Dual Data Rate 4 (DDR4), Low Power Dual Data Rate 2 (LPDDR2) and Low Power Dual Data Rated 3 (LPDDR3) use a dedicated chip select pin (CS#) per rank of memory. This enables a memory controller to send a command that is broadcasted to all ranks of memory by asserting all of the CS# pins. Examples of commands that are typically broadcasted by the memory controller to the memory ranks are MRW (mode register write), self refresh entry and precharge all.
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 embodiments. However, various embodiments of the invention 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 embodiments of the invention. Further, various aspects of embodiments of the invention 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.
Memory technologies such as Wide Input/Output 2 (WIO2) and LPDDR4 may eliminate CS# pins in order to reduce pin count in the memory controller. A single rank select pin (RS) in the memory controller may be used to broadcast commands to designated memory ranks. In a two rank memory system if the RS pin=0 then the command is for the first rank and if RS=1 then the command is for the second rank.
However, eliminating the multiple chip select (CS#) pins in the memory controller effectively eliminates the ability to broadcast commands to all ranks in a memory system. Accordingly, encoding techniques which can broadcast commands to all ranks may find utility, e.g., in memory systems.
The electronic device 100 includes system hardware 120 and memory 130, which may be implemented as random access memory and/or read-only memory. System hardware 120 may include one or more processors 122, bus structures 123, one or more graphics processors 124, memory systems 125, network interfaces 126, and input/output interfaces 127. In one embodiment, processor 122 may be embodied as an Intel® Core2 Duo® processor available from Intel Corporation, Santa Clara, Calif., USA. As used herein, the term “processor” means any type of computational element, such as but not limited to, a microprocessor, a microcontroller, a complex instruction set computing (CISC) microprocessor, a reduced instruction set (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or any other type of processor or processing circuit.
Bus structures 123 connect various components of system hardware 120. In one embodiment, bus structures 123 may be one or more of several types of bus structure(s) including a memory bus, a peripheral bus or external bus, and/or a local bus using any variety of available bus architectures including, but not limited to, 11-bit bus, Industrial Standard Architecture (ISA), Micro-Channel Architecture (MSA), Extended ISA (EISA), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), Universal Serial Bus (USB), Advanced Graphics Port (AGP), Personal Computer Memory Card International Association bus (PCMCIA), and Small Computer Systems Interface (SCSI).
Graphics processor(s) 124 may function as adjunct processor that manages graphics and/or video operations. Graphics processor(s) 124 may be integrated onto the motherboard of electronic device 100 or may be coupled via an expansion slot on the motherboard.
Memory systems 125 may comprise local memory, e.g., cache memory, one or more forms of volatile memory and nonvolatile memory, as described below.
In one embodiment, network interface(s) 126 could be a wired interface such as an Ethernet interface (see, e.g., Institute of Electrical and Electronics Engineers/IEEE 802.3-2002) or a wireless interface such as an IEEE 802.11a, b or g-compliant interface (see, e.g., IEEE Standard for IT-Telecommunications and information exchange between systems LAN/MAN—Part II: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications Amendment 4: Further Higher Data Rate Extension in the 2.4 GHz Band, 802.11G-2003). Another example of a wireless interface would be a general packet radio service (GPRS) interface (see, e.g., Guidelines on GPRS Handset Requirements, Global System for Mobile Communications/GSM Association, Ver. 3.0.1, December 2002).
I/O interface(s) 127 may be implemented on one or more I/O devices, e.g., a display, a touch screen, one or more speakers, a keyboard, a mouse, a touchpad, or the like.
Memory 130 may store an operating system 140 for managing operations of electronic device 100. In one embodiment, operating system 140 includes a hardware interface module 154, e.g., one or more operating system device drivers, that provides an interface to system hardware 120. In addition, operating system 140 may include a file system 150 that manages files used in the operation of electronic device 100 and a process control subsystem 152 that manages processes executing on electronic device 100.
Operating system 140 may include (or manage) one or more communication interfaces 144 that may operate in conjunction with system hardware 120 to transceive data packets and/or data streams from a remote source. Operating system 140 may further include a system call interface module 142 that provides an interface between the operating system 140 and one or more application modules resident in memory 130. Operating system 140 may be embodied as a UNIX operating system or any derivative thereof (e.g., Linux, Solaris, etc.) or as a Windows® brand operating system, or other operating systems.
In some embodiments memory 130 may store one or more applications 160 which may execute on the one or more processors 122 under the supervision of operating system 140. The applications 160 may be embodied as logic instructions stored in a tangible, non-transitory computer readable medium (i.e., software or firmware) which may be executable on one or more of the processors 122. Alternatively, these applications may be embodied as logic on a programmable device such as a field programmable gate array (FPGA) or the like. Alternatively, these applications may be reduced to logic that may be hardwired into an integrated circuit.
Memory interface 224 is coupled to one or more remote memory devices 240A, 240B, which may be referred to collectively by reference numeral 240, by a communication bus 260. Memory devices 240 may comprise a command decoder 242 and one or more memory arrays 250. In various embodiments, memory arrays 250 may be implemented using dynamic random access memory (DRAM) memory, e.g., low-power double data rate (LPDDR) DRAM, Wide Input/Output (WIO) DRAM. By way of example, in some embodiments the memory device(s) 240 may comprise one or more direct in-line memory modules (DIMMs) coupled to a memory channel which provides a communication link to command decoder 242. The specific configuration of the memory arrays 250 in the memory devices 240 is not critical.
By way of example, referring to
In some embodiments logic in the memory controller 222 and the command decoder 242 cooperate to implement methods to broadcast commands to multiple ranks 274, 276 in DIMMs 240. More particularly, in some embodiments logic in the memory controller 222 implements operations to insert a first predetermined value into an all ranks parameter in a memory command before the memory command is passed to the memory devices 240 and the command decoder 242 implements operations to broadcast the memory command to all ranks in the memory devices 240 when the all ranks parameter includes the predetermined value. In some embodiments the memory broadcast parameter may be implemented by setting an all ranks parameter to either a logic low (i.e., a “0”) if the memory command is not to be broadcast, or to a logic high (i.e., a “1”) if the memory command is to be broadcast.
Operations implemented by memory controller 222 and the command decoder 242 will be described with reference to
At operation 410 the memory controller 222 determines whether the command is to be broadcast to all ranks 274, 276. In some embodiments the controller 222 may be configured to encode specific memory commands as “all rank” broadcast commands, which may in some cases be broadcast to all ranks 274, 276 in a memory device.
If, at operation 415, the message it so be broadcast to all ranks, then control passes to operation 420 and the memory controller 222 inserts a first predetermined value into an all ranks parameter in the memory command. As described above, in some embodiments the memory controller 222 inserts a binary “1” into an all ranks bit in the memory command. By contrast, the message is not to be broadcast to all ranks then control passes to operation 425 and the memory controller 222 inserts a second predetermined value into an all ranks parameter in the memory command. As described above, in some embodiments the memory controller 222 inserts a binary “0” into an all ranks bit in the memory command.
At operation 430 the memory command is transmitted from the memory controller 222 to the memory devices 240. By way of example, memory controller 222 may place the command on communication bus 260 via the memory interface 224.
At operation 440 the command decoder 242 receives the memory command, and at operation 445 the command decoder 242 determines whether the command is to be broadcast to all ranks by examining the all ranks parameter. If, at operation 445, the all ranks parameter is set to the first predetermined value (e.g., a logic “1”) then control passes to operation 450 and the memory command is broadcast to all ranks in the memory devices 240. Stated otherwise, if the all ranks parameter is set to the first predetermined value then the controller disregards the rank select parameter and broadcasts the command to all ranks. By contrast, if at operation 445, the all ranks parameter is set to the second predetermined value (e.g., a logic “0”) then control passes to operation 455 and the memory command is broadcasted to the rank(s) associated with the rank select parameter in the memory device(s) 240.
Thus, described herein is a command encoding scheme which enables a memory system in an electronic device to implement command broadcast to all ranks of memory chips in the memory system.
As described above, in some embodiments 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 embodiment of the invention, the graphics interface 614 may communicate with the display device 616 via an accelerated graphics port (AGP). In an embodiment of the invention, 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 embodiments of the invention, 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 embodiments of the invention. 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 embodiments of the invention.
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 embodiment, 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 embodiment, 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 embodiment, 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 embodiment, 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 embodiment, 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 embodiment, 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 embodiment. The core 706 may also include a retirement unit 810. The retirement unit 810 may retire executed instructions after they are committed. In an embodiment, 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 embodiments, 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 embodiment, 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 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 examples pertain to further embodiments.
Example 1 is memory controller comprising logic to insert a first predetermined value into an all ranks parameter in a memory command and transmit the memory command to a memory device.
In Example 2, the subject matter of Example 1 can optionally include logic to determine whether a memory command is to be broadcast to all ranks in a memory device, and in response to a determination that the memory command is to be broadcast to all ranks in a memory device, insert the first predetermined value into the all ranks parameter.
In Example 3, the subject matter of any one of Examples 1-2 can optionally include a memory command which comprises at least one of an activate command, a precharge command, or a refresh command.
In Example 4, the subject matter of any one of Examples 1-3 can optionally include an arrangement in which the command is transmitted to the memory device via a memory interface.
Example 5 is an apparatus comprising a processor and a memory control logic to insert a first predetermined value into an all ranks parameter in a memory command and transmit the memory command to a memory device.
In Example 6, the subject matter of Example 5 can optionally include logic to determine whether a memory command is to be broadcast to all ranks in a memory device, and in response to a determination that the memory command is to be broadcast to all ranks in a memory device, insert the first predetermined value into the all ranks parameter.
In Example 7, the subject matter of any one of Examples 5-6 can optionally include a memory command which comprises at least one of an activate command, a precharge command, or a refresh command.
In Example 8, the subject matter of any one of Examples 5-7 can optionally include an arrangement in which the command is transmitted to the memory device via a memory interface.
Example 9 is a command decoder comprising logic to receive a memory command comprising an all ranks parameter and broadcast the memory command to all ranks in a memory device coupled to the command decoder when the all ranks parameter holds a first predetermined value.
In Example 10, the subject matter of Example 9 can optionally include logic to disregard the rank select parameter when the all ranks parameter holds the first predetermined value.
In Example 11, the subject matter of any one of Examples 9-10 can optionally include logic to apply the rank select parameter when the all ranks parameter holds a second predetermined value.
Example 12 is a memory device, comprising a plurality of memory chips organized into two or more memory ranks, a command decoder coupled to the plurality of memory chips comprising logic to receive a memory command comprising an all ranks parameter, and broadcast the memory command to all ranks in a memory device coupled to the command decoder when the all ranks parameter holds a first predetermined value.
In Example 13, the subject matter of Example 12 can optionally include logic to disregard the rank select parameter when the all ranks parameter holds the first predetermined value.
In Example 14, the subject matter of any one of Examples 12-13 can optionally include logic to apply the rank select parameter when the all ranks parameter holds a second predetermined value.
Example 15 is an electronic device, comprising at least one electronic component, a memory controller comprising logic to insert a predetermined value into an all ranks parameter in a memory command and transmit the memory command to a memory device, the memory device comprising a plurality of memory chips organized into two or more memory ranks a command decoder coupled to the plurality of memory chips comprising logic to receive the memory command comprising the all ranks parameter and broadcast the memory command to all ranks in the memory device coupled to the command decoder when the all ranks parameter holds a first predetermined value.
In Example 16, the subject matter of Example 15 can optionally include logic to determine whether a memory command is to be broadcast to all ranks in a memory device, and in response to a determination that the memory command is to be broadcast to all ranks in a memory device, insert the first predetermined value into the all ranks parameter.
In Example 17, the subject matter of any one of Examples 15-16 can optionally include a memory command which comprises at least one of an activate command, a precharge command, or a refresh command.
In Example 18, the subject matter of any one of Examples 15-17 can optionally include an arrangement in which the command is transmitted to the memory device via a memory interface.
In Example 19, the subject matter of any one of Examples 15-18 can optionally include an arrangement in which the memory command further comprises a rank select parameter, and the command decoder further comprises logic to disregard the rank select parameter when the all ranks parameter holds the first predetermined value.
In Example 20, the subject matter of any one of Examples 15-19 can optionally include logic to apply the rank select parameter when the all ranks parameter holds a second predetermined value.
In various embodiments of the invention, the operations discussed herein, e.g., with reference to
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least an implementation. The appearances of the phrase “in one embodiment” in various places in the specification may or may not be all referring to the same embodiment.
Also, in the description and claims, the terms “coupled” and “connected,” along with their derivatives, may be used. In some embodiments of the invention, “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 embodiments of the invention 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.