Non-volatile semiconductor memory allowing user to enter various refresh commands
AssigneeSharp Kabushiki Kaisha
InventorKatsumi Fukumoto
Life of this patent
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Abstract
In a non-volatile flash memory having memory cells divided into blocks, a command state machine decodes a refresh command entered, and sends a decoded result to a write state machine. The write state machine performs a refresh operation in accordance with the decoded result. The nonvolatile flash memory allows a user to enter the refresh command. The refresh command includes “SINGLE BLOCK REFRESH”, “FULL CHIP REFRESH”, “REFRESH SUSPEND”, and “REFRESH RESUME”.
Claims19
A non-volatile semiconductor memory to write memory cells block by block or sector by sector by a command method in which a predetermined operation is performed according to data and/or an address entered from outside according to a bus cycle, comprising:
- a refresh command setting unit outputting a refresh command in accordance with a command entered by a user, said refresh command including a command to perform a refresh operation, a command to suspend the refresh operation, and a command to resume the refresh operation;
- a refresh unit performing a refresh operation on a selected block or sector, said refresh unit starting and stopping in accordance with the refresh command received from said refresh command setting unit.
Dependencies are inferred from the claim text.