Method combining once-writeable and rewriteable information storage to support data processing
An information storage arrangement that combines rewriteable storage with one-time programmable (OTP) storage is managed in a manner that makes judicious use of the OTP storage. It is therefore possible to exploit the economic advantage associated with OTP storage, while also avoiding storage capacity losses that would otherwise be associated with OTP storage.
1. A method for archiving information from a rewritable memory to a one-time-programmable memory, the method comprising:
(a) determining if available storage capacity in a rewritable memory is at a threshold amount;
(b) if the available storage capacity in the rewritable memory is at the threshold amount:
(b1) retrieving information stored in the rewritable memory; and
(b2) writing the information in a one-time-programmable memory;
wherein the rewritable memory is a flash memory device, and wherein the rewritable memory and the one-time-programmable memory are provided together as a unit that is configured for removable connection to a mobile host apparatus.
2. The method of claim 1 further comprising:
making available locations in the rewritable memory that store the information.
3. The method of claim 1 further comprising:
selecting the information to retrieve from the rewritable memory.
4. The method of claim 3 , wherein the information is selected based on a selection condition.
5. The method of claim 4 , wherein the selection condition comprises likelihood to change.
6. The method of claim 4 , wherein the selection condition comprises likelihood to be deleted.
7. The method of claim 4 , wherein the selection condition comprises access history of the information.
8. The method of claim 7 , wherein the access history comprises write access history.
9. The method of claim 7 , wherein the access history comprises read access history.
10. The method of claim 7 , wherein the access history comprises a combination of write access history and read access history.
11. The method of claim 4 , wherein the selection condition comprises a least-frequently-accessed criterion.
12. The method of claim 4 , wherein the selection condition comprises a least-recently-accessed criterion.
13. The method of claim 4 , wherein the selection condition comprises a combination of a most-frequently-accessed criterion and a least-recently-accessed criterion.
14. The method of claim 1 further comprising repeating (a) and (b).
15. The method of claim 1 further comprising, before (a), determining that the information should be stored in the rewritable memory instead of the one-time-programmable memory.
16. The method of claim 1 , wherein the rewritable memory and the one-time-programmable memory are physical partitions of a memory.
17. A method for archiving information from a rewritable memory to a one-time-programmable memory, the method comprising:
(a) determining if a rewritable memory is too full;
(b) if the rewritable memory is too full:
(b1) selecting information to retrieve from the rewritable memory;
(b2) retrieving the information from the rewritable memory;
(b3) writing the information in a one-time-programmable memory; and
(b4) making available locations in the rewritable memory that store the information;
wherein the rewritable memory is a flash memory device, and wherein the rewritable memory and the one-time-programmable memory are provided together as a unit that is configured for removable connection to a mobile host apparatus.
18. The method of claim 17 , wherein the information is selected based on one or more of the following: likelihood to change, likelihood to be deleted, access history, write access history, read access history, a combination of write access history and read access history, a least-frequently-accessed criterion, a least-recently-accessed criterion, and a combination of a most-frequently-accessed criterion and a least-recently-accessed criterion.
19. The method of claim 17 further comprising repeating (a) and (b).
20. The method of claim 17 further comprising, before (a), determining that the information should be stored in the rewritable memory instead of the one-time-programmable memory.
21. The method of claim 17 , wherein the rewritable memory and the one-time-programmable memory are physical partitions of a memory.