06230233 is referenced by 507 patents and cites 86 patents.

A mass storage system made of flash electrically erasable and programmable read only memory (“EEPROM”) cells organized into blocks, the blocks in turn being grouped into memory banks, is managed to even out the numbers of erase and rewrite cycles experienced by the memory banks in order to extend the service lifetime of the memory system. Since this type of memory cell becomes unusable after a finite number of erase and rewrite cycles, although in the tens of thousands of cycles, uneven use of the memory banks is avoided so that the entire memory does not become inoperative because one of its banks has reached its end of life while others of the banks are little used. Relative use of the memory banks is monitored and, in response to detection of uneven use, have their physical addresses periodically swapped for each other in order to even out their use over the lifetime of the memory.

Title
Wear leveling techniques for flash EEPROM systems
Application Number
7/759212
Publication Number
6230233 (B1)
Application Date
September 13, 1991
Publication Date
May 8, 2001
Inventor
Anil Gupta
Irvine
CA, US
Gregory B Thelin
Garden Grove
CA, US
Robert D Norman
San Jose
CA, US
Karl M J Lofgren
Newport Beach
CA, US
Assignee
Sandisk Corporation
CA, US
IPC
G06F 12/02
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