System architecture with multiple memory types, including programmable impedance memory elements
View Patent ↗A system can include a first memory section comprising a plurality of volatile memory cells accessible via a first data path having a first bit width; a second memory section comprising a plurality of programmable impedance memory cells, each having at least one solid electrolyte layer; and a second data path configured to transfer data between the first and second memory sections independent of the first data path, the second data path having a greater bit width than the first data path.
1. A system, comprising:
a first memory section comprising a plurality of volatile memory cells accessible via a first data path having a first bit width;
a second memory section comprising a plurality of programmable impedance memory cells, each having at least one solid electrolyte layer; and
a second data path configured to transfer data between the first and second memory sections independent of the first data path, the second data path having a greater bit width than the first data path; and
a transfer circuit comprising a data copy engine configured to automatically transfer a block of data from the first memory section to the second memory section in response to a save command.
2. The system of claim 1 , wherein:
the second data path has a bit width of no less than 512 bits.
3. The system of claim 1 , wherein:
the first memory section comprises dynamic random access memory (DRAM) cells.
4. The system of claim 1 , wherein:
the second memory section comprises conductive bridging random access memory (CBRAM) type cells.
5. The system of claim 1 , wherein:
a storage capacity of the first memory section is different than that of the second memory section.
6. The system of claim 1 , wherein:
the transfer circuit is further configured to transfer data between a first address space of the first memory section and a second address space of the second memory section via the second data path.
7. The system of claim 6 , wherein:
the first and second address spaces are programmable.
8. The system of claim 1 , wherein:
the data copy engine is further configured to automatically transfer a block of data between the second memory section and the first memory section, via the second data path, in response to at least one predetermined condition.
9. The system of claim 8 , wherein:
the at least one predetermined condition is selected from the group of: a restore command that transfers a block of data from the second memory section to the first memory section; a timer value; a wear value, and an alarm value indicating a predetermined state of the system.
10. A system, comprising:
a first memory section comprising a plurality of volatile memory cells;
a second memory section comprising a plurality of programmable impedance memory cells, each having at least one solid electrolyte layer, the second memory section being coupled to the first memory section via a first data path that is configured to transfer N bits in parallel; and
at least one interface configured to transfer data between at least the first memory section and a second data path, the second path configured to transfer M bits in parallel, where N>M; and
program circuits configured to automatically program a block of data values from the first memory section into the second memory section in response to at least at least an alarm value indicating a predetermined state of the system.
11. The system of claim 10 , wherein:
the first memory section comprises dynamic random access memory (DRAM) cells; and
the at least one interface comprises a DRAM device interface that includes a chip select (CS) input, a column address strobe (CAS) input, a row address strobe (RAS) input, and a write enable (WE) input.
12. The system of claim 10 , wherein:
the at least one interface includes a first select input that enables accesses to the first memory section and a second select input that enables accesses to the second memory section.
13. The system of claim 10 , wherein:
the second memory section is configured to transfer data in response to sideband signal paths different from those received at the at least one interface.
14. The system of claim 10 , further including:
a transfer circuit configured to automatically transfer a predetermined block of data between the first memory section and the second memory section;
a comparator circuit configured to generate a compare result in response to a comparison between a received address to a current data transfer point; and
access circuits configured to selectively enable access to the first memory section or second memory section according to the compare result.
15. The system of claim 10 , further including:
the program circuits are further configured to program data values into the second memory section according to one of at least two different data retention times in response to at least one predetermined condition.
16. The system of claim 15 , wherein:
the at least one predetermined condition includes any selected from the group of: a timer value corresponding to a time from a last program operation of a predetermined group of memory cells, a wear value corresponding a number of program operations performed on a predetermined group of programmable impedance memory cells, and a received command.
17. A method, comprising:
transferring data between at least a volatile memory section and a first data path in response to first data access commands; and
transferring a predetermined data block between the volatile memory section and a programmable impedance memory section via a second data path in response to at least one predetermined condition; wherein
the second data path has a larger bandwidth than the first data path, and the programmable impedance memory section comprises memory elements having at least one solid electrolyte layer, and
the at least one predetermined condition includes a save command that transfers a block of data from the volatile memory section to the programmable impedance memory section.
18. The method of claim 17 , wherein:
the at least one predetermined condition is further selected from the group of: a restore command that transfers a block of data from the programmable impedance memory section to the volatile memory section; a timer value; a wear value, and an alarm value indicating a predetermined state of a system containing the volatile memory section and the programmable impedance section.
19. The method of claim 17 , wherein:
the volatile memory section comprises dynamic random access memory (DRAM) cells and the programmable impedance memory section comprises conductive bridging random access memory (CBRAM) type cells;
transferring the predetermined data block between the volatile memory section and a programmable impedance memory section includes
generating a sequence of addresses and read commands to access the DRAM cells, and
generating a sequence of addresses and program commands to access the CBRAM cells.
20. The method of claim 17 , wherein:
transferring the predetermined block of data includes maintaining a current location value corresponding to the portion of the block copied; and
in response to an access command to the volatile section while the predetermined block of data is being transferred,
comparing the current location to a received address to generate a compare result, and
accessing either the volatile memory section or the programmable impedance memory section in response to the compare result.
21. The method of claim 17 , wherein:
transferring the predetermined block of data includes programming data values into the programmable impedance memory section according to one of at least two different data retention times in response to predetermined conditions.