Systems and methods for refreshing a non-volatile memory using a token
AssigneeMacronix International Co., Ltd.
InventorsMing-Hung Chou, Chia Hsing Chen
Life of this patent
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Abstract
The present invention is related to methods and systems for refreshing non-volatile memories. A refresh token associated with a first wordline is located. A determination is made as to whether a first cell current for a first cell coupled to the first wordline is within a first range. At least partly in response to determining that the first cell current is within the first range, the first cell is refreshed.
Claims22
A method of refreshing non-volatile memory cells, the method comprising:
- locating a refresh token associated with a first wordline;
- determining if a first cell current for a first cell coupled to the first wordline is within a first range;
- and
- refreshing the first cell at least partly in response to determining that the first cell current is within the first range.
A non-volatile memory circuit comprising:
- a first wordline coupled to a first row of memory data cells;
- a first refresh token cell coupled to the first wordline;
- a second wordline coupled to a second row of memory data cells;
- a second refresh token cell coupled to the second wordline;
- and
- a refresh circuit configured to pass a refresh token bit from the first refresh token cell to the second refresh token cell after a first memory operation.
A method of operating a non-volatile memory, the method comprising:
- performing an erase and program operation on a first byte coupled to a first wordline;
- performing a refresh of at least a first cell coupled to a second wordline, the refresh including:
- locating a refresh bit associated with a second wordline;
- refreshing a second cell, the second cell coupled to the second wordline;
- erasing the refresh bit;
- and
- associating the refresh bit with a third wordline.
A non-volatile memory circuit comprising:
- a first conductor coupled to a first row of memory data cells;
- a first refresh token storage element associated with the first row of memory data cells;
- a second conductor coupled to a second row of memory data cells;
- a second refresh token storage element associated with the second row of memory data cells;
- and
- a refresh circuit configured to pass a refresh token bit from the first refresh token storage element to the second refresh token storage element after a first memory operation.
Dependencies are inferred from the claim text.