Reconfigurable memory arrays having programmable impedance elements and corresponding methods
View Patent ↗A memory device may include a plurality of memory cells each having elements with at least one solid ion conductor programmable between at least two different impedance states for at least two different data retention times, the plurality of memory cells being dividable into a plurality of portions, each portion being separately configurable for one of the data retention times.
1. A memory device, comprising:
a plurality of memory cells each having elements with at least one solid ion conductor programmable between at least two different impedance states for at least two different data retention times, the plurality of memory cells being dividable into a plurality of portions by configuration values corresponding to each portion, each portion being separately configurable for one of the data retention times; and
configuration registers configured to store each configuration value, each configuration register including storage locations and a write path for receiving configuration values for storage.
2. The memory device of claim 1 , further including:
a plurality of nonvolatile storage structures, each nonvolatile storage structure storing a configuration value for a portion.
3. The memory device of claim 2 , wherein:
the nonvolatile storage structures are selected from the group of: fusible links, anti-fuses, and nonvolatile memory cells.
4. The memory device of claim 1 , wherein:
the memory cells further include a lockable portion having memory cells programmable to store the configuration values, the lockable portion being accessible under predetermined conditions not applied to the other of the memory cells.
5. The memory device of claim 1 , wherein:
the configuration values comprise configuration address values.
6. The memory device of claim 5 , further including:
a plurality of address range comparators that compare a received address to the configuration address values.
7. The memory device of claim 1 , further including:
an input coupled to another device that receives at least one of the configuration values.
8. The memory device of claim 1 , further including:
the plurality of memory cells are physically divided into sections, each section coupled to a corresponding write circuit, the write circuit being alterable to program the elements of its section to one of the data retention times.
9. The memory device of claim 8 , wherein:
each write circuit is formed in a fabrication step to program its elements to one of the data retention times.
10. A memory device comprising:
a plurality of memory cells each having elements with at least one solid ion conductor programmable between at least two different impedance states for at least two different data retention times, the plurality of memory cells being dividable into a plurality of portions by configuration values corresponding to each portion, each portion being separately configurable for one of the data retention times; and
a plurality of write circuits coupled to the memory cells, each write circuit configured to select between the data retention times in response to at least one of a plurality of configuration values.
11. The memory device of claim 10 , further including:
a plurality of read circuits coupled to the memory cells, each read circuit configured to select between different data determining threshold limits in response to at least one of the configuration values.
12. A memory device comprising:
a plurality of memory cells each having elements with at least one solid ion conductor programmable between at least two different impedance states for at least two different data retention times, the plurality of memory cells being dividable into a plurality of portions by configuration values corresponding to each portion, each portion being separately configurable for one of the data retention times; and
an address translator configured to translate a first range of logical addresses into physical addresses of a first portion programmed to a first data retention time and translate a second range of logical addresses into physical addresses of a second portion programmed to a second data retention time different from the first data retention time.
13. The memory device of claim 10 , further including:
the memory cells are accessed by access circuits coupled to the memory cells, the access circuits being configurable for different access operations corresponding to the data retention time of the corresponding memory cells.
14. The memory device of claim 13 , wherein:
configuring the access circuits for different access operations includes altering circuit features selected from: a read threshold voltage, a read threshold current, a write voltage, a write current, a write duration, and a read duration.
15. An integrated circuit method, comprising:
forming access circuits in an integrated circuit substrate, the access circuits configurable to program corresponding memory elements comprising a solid ion conductor between at least two different data retention times; and
configuring at least two access circuits to program their corresponding memory elements to one of the data retention times with configuration information stored by the integrated circuit by writing configuration information to configuration registers on the integrated circuit.
16. The method of claim 15 , wherein:
configuring at least two access circuits further includes manufacturing steps selected from the group: setting the configuration information with a fabrication mask, opening fusible links, closing anti-fuse links.
17. The method of claim 15 , wherein:
configuring at least two access circuits further includes accessing a lockable group of memory elements according to predetermined access steps, programming the memory elements of the lockable group to store the configuration information; wherein
the memory elements of the lockable group are not accessible by standard write operations.
18. The method of claim 15 , wherein:
forming access circuits includes forming write circuits that impart different amounts of energy on corresponding memory elements according to the data retention time to be programmed.
19. The method of claim 15 , wherein:
forming access circuits includes forming read circuits that vary a current or voltage threshold according to a data retention time of corresponding memory elements.
20. The method of claim 15 , wherein:
configuring at least two access circuits includes receiving configuration values from a source external to the integrated circuit.
21. The method of claim 15 , wherein:
configuring at least two access circuits includes altering circuit features selected from: a read threshold voltage, a read threshold current, a write voltage, a write current, a write duration, and a read duration.
22. A method, comprising:
writing data values to different portions of a memory array with a write energy that varies according to a configuration value for each portion, the memory array including elements comprising a solid state ion conductor; and
writing data values to different portions of a memory array includes selecting a write energy based on a comparison between a received address value and a configuration value.
23. The method of claim 22 , wherein:
the received address value corresponds to a physical row address of the memory array.
24. The method of claim 22 , wherein:
the received address value corresponds to a physical column address of the memory array.
25. The method of claim 22 , further including:
reading data values from different portions of the memory array with a read threshold current or voltage that varies according to the configuration value for each portion.
26. The method of claim 22 , wherein:
writing data values to different portions of a memory array includes translating received logical addresses to physical addresses according to the configuration values.