ASIC including vertically stacked embedded non-flash re-writable non-volatile memory
A multiple-type memory is disclosed. The multiple-type memory includes memory blocks in communication with control logic blocks. The memory blocks and the control logic blocks are configured to emulate a plurality of memory types. The memory blocks can be configured into a plurality of memory planes that are vertically stacked upon one another. The vertically stacked memory planes may be used to increase data storage density and/or the number of memory types that can be emulated by the multiple-type memory. Each memory plane can emulate one or more memory types. The control logic blocks can be formed in a substrate (e.g., a silicon substrate including CMOS circuitry) and the memory blocks or the plurality of memory planes can be positioned over the substrate and in communication with the control logic blocks. The multiple-type memory may be non-volatile so that stored data is retained in the absence of power.
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The present invention relates to computing systems and, more particularly, to memory devices.
BACKGROUNDComputing systems typically have different memory type needs. As a result, computing systems usually include different memory devices. For example,
There are continuing efforts to satisfy the memory needs of a system.
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like structural elements.
Although the previous Drawings depict various examples of the invention, the invention is not limited by the depicted examples. Furthermore, the depictions are not necessarily to scale.
DETAILED DESCRIPTIONThe invention can be implemented in numerous ways, including as a system, a method, or an apparatus. In general, the steps of disclosed processes may be performed in an arbitrary order, unless otherwise provided in the claims.
A detailed description of one or more embodiments is provided below along with accompanying figures. The detailed description is provided in connection with such embodiments, but is not limited to any particular example. The scope is limited only by the claims and numerous alternatives, modifications, and equivalents are encompassed. Numerous specific details are set forth in the following description in order to provide a thorough understanding. These details are provided for the purpose of example and the described techniques may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the embodiments has not been described in detail to avoid unnecessarily obscuring the description.
Multiple-Type MemoryThe embodiments described herein provide a multiple-type memory that can emulate more than one memory type. In general, the memory can be partitioned into multiple memory blocks, and as will be explained in more detail below, the memory blocks and their associated control logics can be configured to emulate different memory types.
U.S. patent application Ser. No. 11/095,026, filed Mar. 30, 2005, now U.S. Published Application No. 2006/0171200, and titled “Memory Using Mixed Valence Conductive Oxides,” hereby incorporated by reference in its entirety and for all purposes, describes non-volatile third dimension memory cells that can be arranged in a cross-point array. The application describes a two terminal memory element that changes conductivity when exposed to an appropriate voltage drop across the two terminals. The memory element includes both a mixed ionic electronic conductor and a layer of material that has the bulk properties of an electrolytic tunnel barrier (properties of an electronic insulator and an ionic conductor). A voltage drop across the electrolytic tunnel barrier causes an electrical field within the mixed ionic electronic conductor that is strong enough to move oxygen ions out of the mixed ionic electronic conductor and into the electrolytic tunnel barrier. Oxygen depletion causes the mixed ionic electronic conductor to change its conductivity. Both the electrolytic tunnel barrier and the mixed ionic electronic conductor do not need to operate in a silicon substrate, and, therefore, can be fabricated above circuitry being used for other purposes (e.g., selection circuitry, sense amps, and address decoders). A memory is “third dimension memory” when it is fabricated above other circuitry components, the components usually including a silicon substrate, polysilicon layers and, typically, metallization layers.
The two-terminal memory elements can be arranged in a cross-point array such that one terminal is electrically coupled with an x-direction line and the other terminal is electrically coupled with a y-direction line. A stacked cross-point array consists of multiple cross-point arrays stacked upon one another, sometimes sharing x-direction and y-direction lines between layers, and sometimes having isolated lines. When a first write voltage VW1 is applied across the memory element, (typically by applying ½ VW1 to the x-direction line and ½-VW1 to the y-direction line) it switches to a low resistive state. When a second write voltage VW2 is applied across the memory element, (typically by applying ½ VW2 to the x-direction line and ½-VW2 to the y-direction line) it switches to a high resistive state. Typically, memory elements using electrolytic tunnel barriers and mixed ionic electronic conductors require VW1 to be opposite in polarity from VW2.
Control logic blocks 214-218 are located within logic plane 228 of multiple-type memory 202 and include circuitries (e.g., sense amplifiers, address units, transistors, decoders, capacitors, multiplexers, drivers, power supplies, etc.) that provide control and interface functions. Each memory block 204, 205, 206, 207 or 208 corresponds to an associated control logic block 214, 215, 216, 217 or 218, respectively, and both the memory block and its associated control logic block are configured to emulate a memory type. Specifically, each memory block 204, 205, 206, 207 or 208 is logically in communication with an associated control logic block 214, 215, 216, 217 or 218, respectively. For example, as shown in
Each memory block 204, 205, 206, 207 or 208 and its associated control logic block 214, 215, 216, 217 or 218, respectively, are isolated from the other memory blocks and control logic blocks. Accordingly, each memory block 204, 205, 206, 207 or 208 and its associated control logic block 214, 215, 216, 217 or 218, respectively, are configured to function as a separate and independent memory devices. In other words, each memory block 204, 205, 206, 207 or 208 and its associated control logic block 214, 215, 216, 217 or 218, respectively, are configured to function as a single memory type. Memory blocks 204-208 and their associated control logic blocks 214-218 can emulate any suitable types of memory. An exemplary memory type is a dynamic random access memory (DRAM), which is a type of volatile dynamic memory that essentially stores each bit (i.e., data bit) in a capacitor and one or more transistors. Another exemplary memory type is a static random access memory (SRAM), which is a type of volatile memory that basically stores each bit in a series of flip-flops. Other exemplary memory types that can be emulated by memory blocks 204-208 and control logic blocks 214-218 include but are not limited to serial memories (e.g., EEPROM) and non-volatile memories (e.g., FLASH memory).
Still referring to
Each control logic block 310, 311, 312, or 313 is configured to emulate the control and interface functions of an EEPROM, a FLASH memory, a DRAM, or an SRAM. As discussed above, the control and interface functions of a memory type can be emulated by varying the circuitries within control logic blocks 310-313 that provide control and interface functions. For example, when compared to other control logic blocks 310-312, SRAM control logic block 313 can include circuitries that are optimized for speed with larger drivers and more sensitive sense amplifiers. In another example, when compared to other control logic blocks 310, 312, and 313, FLASH control logic block 311 can include circuitries that are optimized for power savings.
One or more memory blocks 505-507 can correspond to control logic block 520, and the memory blocks and the control logic block are configured to emulate a single memory type. Depending on the memory requirements of a system, the memory size of the single memory type can be adjusted. For example, if the system requires two megabytes of a memory type, then memory block 507 is configured to correspond with control logic block 520. If the system further requires an additional two megabytes of the same memory type, then both memory blocks 506 and 507 are allocated to the memory type and, as such, both the memory blocks 506 and 507 are configured to correspond with control logic block 520. If the system requires six megabytes of the same memory type, then memory blocks 505-507 are configured to correspond with control block 520. Accordingly, one or more memory blocks 505-507 can be dynamically allocated to the same memory type depending on the memory needs of a system.
The components included in disk controller 612 and peripheral devices 650 (e.g., processors 606 and 652, data path controller 604, SCSI controllers 654, etc.) can be in communication within the disk controller 612 or within the peripheral devices through common buses. It should be appreciated that fibre channel controller 602 provides the processing and hardware control for fibre channel technology, which is a technology for transmitting data between computing devices at high data rates. Data path controller 604 (e.g., a direct memory access (DMA) controller) essentially is a processor that processes the transfer of data to and from multiple-type memory 608 and peripheral devices. Similarly, SCSI controllers 654 included in peripheral devices 650 control data transfers between components 631 on SCSI bus interfaces 658.
Fibre channel controller 602, data path controller 604, SCSI controllers 654, and processors 606 and 652 of system 601 can have different memory type needs. For instance, fibre channel controller 602 uses an EEPROM during system boots, while processors 606 and 652 use FLASH memory for system boots and for storing key operating tables. Additionally, processors 606 and 652 use SRAM for fast, temporary storage operations and use DRAM to store packets, data, and some key operation tables of the processor. With multiple-type memories 608 and 656 that are configured to emulate a variety of memory types (e.g., EEPROM, SRAM, FLASH, DRAM, etc.), components within disk controller 612 and peripheral devices 650 can access the multiple-type memories for all their memory type needs. For example, as shown in
In summary, the above-described embodiments provide multiple-type memories. To satisfy the various memory type needs of a system, a multiple-type memory is partitioned into separate memory blocks that are configured to emulate the various memory types. As discussed above, the memory blocks of the multiple-type memory can be dynamically allocated. Accordingly, in addition to meeting the different memory type needs of a system, the multiple-type memory can also meet and adapt to the changing memory requirements of a system. Additionally, a single multiple-type memory has a smaller profile when compared to the space occupied by multiple memory devices. Processing power is also more efficiently used when accessing the multiple-type memory because accessing one multiple-type memory requires less processing power when compared to accessing multiple memory devices. As a result, when compared to the access of multiple memory devices, the use of a multiple-type memory saves energy, reduces processing power, and reduces the physical size of a system.
Memory Address Decoder and Look-Up TableThe embodiments described herein provide methods, circuitries, and one or more look-up tables for selecting a memory address range within a system. As will be explained in more detail below, a memory can include decode logic or look-up table to identify a memory address to which a memory (e.g., a main memory or a particular expansion memory) is to respond.
In general, compare logic 914 is configured to decode a bit of memory address to memory select value 950 which indicates one memory. As shown in
The OR gate 906 is configured to output memory select value 950 based on output of selection circuitry 904 and to disregard parameter 944. As discussed above, disregard parameter 944 specifies whether the bit outputted from selection circuitry 904 should be ignored. Thus, if decode logic 814 disregards the bit outputted from selection circuitry 904, then disregard parameter 944 is enabled such that OR gate 906 outputs the disregard parameter, which indicates to the decode logic that the bit is irrelevant and should be ignored. On the other hand, if the bit outputted from selection circuitry 904 is relevant, then disregard parameter 944 is disabled such that OR gate 906 outputs the bit value from the selection circuitry.
Still referring to
Decode logic 814 basically compares a decoded memory select value with a predetermined memory select value specified by memory select parameters (e.g., polarity select parameter 942, disregard parameter 944, etc.). If the decoded memory select value matches the predetermined memory select value, then decode logic 814 outputs memory select value 920. However, if the decoded memory select value is different from the predetermined memory select value, then decode logic 814 outputs a non-select value.
To further illustrate the above-described embodiments, an exemplary decoding operation of a sixteen bit memory address is provided. In this exemplary operation, the sixteen bit memory address assigned to a decode logic, such as decode logic 814, ranges from 0000 0100 0000 0000 to 0001 1111 1111 1111 with memory addresses 0 to 15 from right to left. A portion of the sixteen bit memory address is decoded to a memory select value, such as memory select value 920. It should be appreciated that all or any suitable portion of memory address can be decoded. For example, a portion may include the most significant bits or the least significant bits. In this example, the most significant bits with memory addresses 10-15 are decoded to a memory select value. Bits associated with memory addresses 0-9 are not relevant and, therefore, not decoded. Three decode banks (e.g., decode bank 916) are enabled to decode the six bits with memory addresses 10-15. For example, with decode bank 0 enabled (e.g., enabled by enable bank decode parameter 946), bits with memory addresses 11-15 inverted (e.g., inverted by polarity select parameter 942), and the disregard parameter (e.g., disregard parameter 944) on all memory addresses 10-15 disabled, decode logic 814 outputs a memory select value of 0000 01. Further, with decode bank 1 enabled, bits with memory addresses 12-15 inverted, bit with memory address 11 not inverted, and the disregard parameter for bit with memory address 10 enabled, decode logic outputs a memory select value of 0000 1x, where “x” represents a bit that is ignored. Finally, with decode bank 2 enabled, bit with memory address 12 not inverted, and the disregard parameter for bits with memory addresses 10 and 11 enabled, decode logic outputs a memory select value of 0001 xx. Decode banks 3, 4, and 5 are disabled and enable memory select value 954 is set. With the above-described memory select parameters, decode logic 814 can recognize the specified memory select value from a memory address and respond by selecting a memory when a bus match is found. If a match is not found, then decode logic 814 outputs a non-select value.
As an alternative to the exemplary decoder of
An exemplary look-up table can be implemented using a third dimension memory positioned in one of the memory planes that is vertically disposed over the logic plane. Typically, a size of the look-up table is small relative to other arrays in the memory plane and therefore requires minimal area to implement. The memory select values can be set in a variety of ways. As one example, the memory select values can be set once at configuration time and then can be permanently used in detecting address ranges for determining memory selects within the array itself. As another example, in some embodiments, it may be desirable to dynamically set the memory select values or to statically set the memory select values at power up. If the main array is used to detect one address range, then the look-up table would have one output. If the array was to support several memory ranges or memory types, then additional memory outputs can be added to the look-up table. One bit being used for each memory range or memory type. In addition to this capability, the look-up table could be used to support a Read only functionality for support of memory types to act as ROMs or write protected RAM memory.
Control logic 964 is coupled with a plurality of input signals that include but are not limited to a chip select CS 981, read/write Rd/Wr 983, bank write enable Bank_Wr_En 975 and generates a plurality of output signals including but not limited to read/write access Access Rd/Wr 977 and write enable Wr_En 976. As one example, a data operation to the third dimension memory would commence with CS 981 going active along with Rd/Wr 977 (e.g., Rd=logic 0 and Wr=logic 1), an address on Address 971, and for a write operation, write data on Write Data 973. If the address on Address 971 maps to the range in look-up table 962, then the Look-up table 962 activates Bank_Wr_En 975 which in turn signals control logic 964 to activate Access Rd/Wr 977 so that the address decoder 966 can generate one of the memory select signals Sel-0, Sel-1, Sel-2, or Sel-3 based on which of the bank enable signals En_Bank-0, En_Bank-1, En_Bank-2, or En_Bank-3 has gone active. For a read operation (e.g., Rd/Wr 983=logic 0), the address decoder 966 selects which memory plane 990, 991, 992, or 993 data is to be read from (i.e., via Rd-0, Rd-1, Rd-2, or Rd-3) and the sense amp and read buffer 970 outputs valid read data on Read Data 979. For a write operation to a memory plane (e.g., Rd/Wr 983=logic 1), Wr_En 976 goes active to enable the Write Data Drivers 968 to drive Write Data 973 to the selected memory plane via Wr-0, Wr-1, Wr-2, or Wr-3.
In some applications, the look-up table 962 can be initialized to block write access to an address or address range in one or more of the memory planes. Accordingly, when a restricted address 971 is received by the look-up table 962, the Bank_Wr_En 975 is deactivated such that the write data drivers 968 are disabled (e.g., Wr_En 976 is inactive). The control logic 964 can be configured to allow read access to the prohibited address(s) such that Access Rd/Wr 977 enables the address decoder 966 to initiate a read operation.
Reference is now made to
One advantage of using the look-up table 962 is that the range of addresses can be tailored to a specific application and the address ranges for each memory plane can be different with some memory planes responding to a larger range of addresses and other memory planes responding to a smaller range of addresses. For example, the address space in memory plane 991 spans a larger range of addresses than the address space in memory planes 990, 992, and 993. Another advantage of using the look-up table 962 is that chip selects for addresses within the address space of the memory planes can be easily generated based on the address received by the look-up table 962. Furthermore, as depicted in
Turning now to
It should be appreciated that the exemplary decode logic of
In the embodiment of
In summary, the above-described embodiments provide decoders and look-up tables to select a memory. By including the decode logic or look-up table in the memory, an external programmable logic device or an external programmable array logic can be eliminated, thereby simplifying logics associated with memory selection.
Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, implementations of the above-described system and techniques is not limited to the details provided. There are many alternative implementations and the disclosed embodiments are illustrative and not restrictive.
Claims
1. An ASIC including embedded non-FLASH re-writable non-volatile memory, comprising:
- a silicon substrate including active circuitry fabricated in a logic plane of the silicon substrate, the active circuitry including a processor, and control logic block circuitry in electrical communication with the processor and configured specifically to emulate one or more memory types and to perform data operations on the one or more memory types; and
- a first memory plane fabricated directly in contact with the silicon substrate and vertically disposed directly over the active circuitry in the logic plane, the first memory plane including at least one two-terminal cross-point memory array embedded in the first memory plane and including a plurality of first conductive array lines and a plurality of second conductive array lines that are electrically coupled with the control logic block circuitry, and a plurality of re-writable non-volatile two-terminal memory elements, each re-writable non-volatile two-terminal memory element is positioned between a cross-point of one of the plurality of first conductive array lines with one of the plurality of second conductive array lines and includes a first terminal electrically coupled with its respective first conductive array line and a second terminal electrically coupled with its respective second conductive array line, and wherein at least a portion of the control logic block circuitry is specifically configured to emulate a FLASH memory type in the at least one two-terminal cross-point memory array, non-volatile data stored in the plurality of re-writable non-volatile two-terminal memory elements comprises system boot data for use by the processor during system boot, and the system boot data is retained the absence of electrical power.
2. The ASIC of claim 1, wherein the non-volatile data stored in the plurality of re-writable non-volatile two-terminal memory elements further comprises operating table data for use by the processor.
3. The ASIC of claim 3, wherein a write data operation on the at least one two-terminal cross-point memory array is operative to write new operating table data to the plurality of re-writable non-volatile two-terminal memory elements.
4. The ASIC of claim 1, wherein a write data operation on the at least one two-terminal cross-point memory array is operative to write new system boot data to the plurality of re-writable non-volatile two-terminal memory elements.
5. The ASIC of claim 1, wherein each re-writable non-volatile two-terminal memory element comprises an electrolytic tunnel barrier in contact with a mixed ionic electronic conductor that includes mobile oxygen ions, the electrolytic tunnel barrier electrically coupled with the first terminal and the mixed ionic electronic conductor electrically coupled with the second terminal.
6. The ASIC of claim 5, wherein the electrolytic tunnel barrier has a thickness that is less than 50 Å.
7. The ASIC of claim 5, wherein the mixed ionic electronic conductor comprises a perovskite.
8. The ASIC of claim 1, wherein the active circuitry comprises CMOS circuitry.
9. The ASIC of claim 1, wherein the active circuitry further comprises direct memory access (DMA) circuitry operative to communicated data between the processor, the at least one two-terminal cross-point memory array, and an external system.
10. The ASIC of claim 1 and further comprising:
- one or more additional memory planes that are vertically stacked above the first memory plane, each additional memory plane is in contact with an adjacent memory plane,
- each additional memory plane includes one or more additional two-terminal cross-point memory arrays embedded therein and having additional pluralities of first and second conductive array lines that are electrically coupled with the control logic block circuitry,
- each additional two-terminal cross-point memory array includes additional pluralities of the re-writable non-volatile two-terminal memory elements positioned between a cross-point of one of the additional plurality of first conductive array lines with one of the additional plurality of second conductive array lines.
11. The ASIC of claim 10, wherein one or more of the two-terminal cross-point memory arrays comprises a stacked cross-point array and the re-writable non-volatile two-terminal memory elements in the stacked cross-point array are positioned in multiple memory layers and the re-writable non-volatile two-terminal memory elements in a memory layer shares at least one of its respective conductive array lines with re-writable non-volatile two-terminal memory elements positioned in an adjacent memory layer.
12. The ASIC of claim 10, wherein the control logic block circuitry is configured to emulate one or more memory types in the one or more additional memory planes, and the memory types are selected from the group consisting of dynamic random access memory (DRAM), static random access memory (SRAM), FLASH memory, and electrically-erasable programmable read-only memory (EEPROM).
13. The ASIC of claim 12, wherein the FLASH memory type that is emulated by the control logic block circuitry stores non-volatile data other than the system boot data.
14. The ASIC of claim 12, wherein for each memory type emulated, the control logic block circuitry includes a separate control logic block circuit that is electrically coupled with the one or more additional two-terminal cross-point memory arrays that the memory type is emulated in.
15. The ASIC of claim 12, wherein non-volatile data stored in all of the memory types is retained in the absence of electrical power.
16. An ASIC including embedded non-FLASH re-writable non-volatile memory, comprising:
- a silicon substrate including active CMOS circuitry fabricated in a logic plane of the silicon substrate, the active CMOS circuitry including a processor, and control logic block circuitry in electrical communication with the processor and configured specifically to emulate one or more memory types and to perform data operations on the one or more memory types, the control logic block circuitry including a plurality of control logic blocks with each control logic block configured to emulate a different memory type; and
- a plurality of memory planes that are in contact with one another and are fabricated directly in contact with the silicon substrate and vertically disposed directly over the active circuitry in the logic plane, the plurality of memory planes including a plurality of two-terminal cross-point memory arrays that are distributed among the plurality of memory planes, each two-terminal cross-point memory array including a plurality of first conductive array lines and a plurality of second conductive array lines that are electrically coupled with one of the plurality of control logic blocks, and a plurality of re-writable non-volatile two-terminal memory elements, each re-writable non-volatile two-terminal memory element is positioned between a cross-point of one of the plurality of first conductive array lines with one of the plurality of second conductive array lines and includes a first terminal electrically coupled with its respective first conductive array line and a second terminal electrically coupled with its respective second conductive array line, and
- wherein a first one of the plurality of control logic blocks is specifically configured to emulate a FLASH memory type in at least one of the two-terminal terminal cross-point memory arrays comprises system boot data for use by the processor during system boot, and the system boot data is retained the absence of electrical power.
17. The ASIC of claim 16, wherein a second one of the plurality of control logic blocks is specifically configured to emulate a dynamic random access memory (DRAM) memory type.
18. The ASIC of claim 16, wherein a third one of the plurality of control logic blocks is specifically configured to emulate a static random access memory (SRAM) memory type.
19. The ASIC of claim 16, wherein a fourth one of the plurality of control logic blocks is specifically configured to emulate an electrically-erasable programmable read-only memory (EEPROM) memory type.
20. The ASIC of claim 16, wherein a fifth one of the plurality of control logic blocks is specifically configured to emulate a FLASH memory type that stores non-volatile data other than the system boot data.
Type: Application
Filed: Oct 12, 2010
Publication Date: Feb 10, 2011
Applicant: UNITY SEMICONDUCTOR CORPORATION (Sunnyvale, CA)
Inventor: Robert Norman (Pendleton, OR)
Application Number: 12/925,062
International Classification: G06F 12/00 (20060101); G06F 9/455 (20060101); G06F 12/02 (20060101);