05479638 is referenced by 315 patents and cites 27 patents.

A semiconductor mass storage device can be substituted for a rotating hard disk. The device avoids an erase cycle each time information stored in the mass storage is changed. (The erase cycle is understood to include, fully programming the block to be erased, and then erasing the block.) Erase cycles are avoided by programming an altered data file into an empty mass storage block rather than over itself as a hard disk would. Periodically, the mass storage will need to be cleaned up. Secondly, a circuit for evenly using all blocks in the mass storage is provided. These advantages are achieved through the use of several flags, a map to directly correlate a logical address of a block to a physical address of that block and a count register for each block. In particular, flags are provided for defective blocks, used blocks, old version of a block, a count to determine the number of times a block has been erased and written and erase inhibit.

Title
Flash memory mass storage architecture incorporation wear leveling technique
Application Number
8/37893
Publication Number
5479638
Application Date
March 26, 1993
Publication Date
December 26, 1995
Inventor
Petro Estakhri
Pleasonton
CA, US
Siamack Nemazie
San Jose
CA, US
Mahmud Assar
Morgan Hill
CA, US
Agent
Haverstock & Associates
Assignee
Cirrus Logic
CA, US
IPC
G06F 12/14
G06F 12/02
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