Dynamic redundancy repair
First Claim
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1. A memory device, comprising:
- a memory array having a plurality of memory cells;
a redundancy array having a plurality of redundancy cells;
a redundancy mapping store having entries to map addresses of memory cells in the memory array to addresses of redundancy cells; and
circuitry coupled to the redundancy array and the memory array, which executes a write operation in response to a write command,the write operation writing a data value having a selected address in the memory array whether or not there is a valid entry for the selected address in the redundancy mapping store, applying a write/verify cycle to a memory cell in the memory array having the selected address, and if the selected memory cell fails verify, then writing the data value to a redundancy cell in the redundancy array and changing or writing an entry to the redundancy mapping store to map the selected address to the redundancy cell.
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Abstract
The disclosed memory device technology for implementing dynamic device repair includes a memory array, a redundancy array and a redundancy mapping store. The memory array includes memory cells and the redundant array includes redundancy cells. The memory device also includes circuitry configured to execute a write operation and a read operation in response to respective commands, using a dynamic redundancy repair method to replace the temporary defective cells in the memory array with the redundancy cells in the redundancy array.
68 Citations
20 Claims
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1. A memory device, comprising:
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a memory array having a plurality of memory cells; a redundancy array having a plurality of redundancy cells; a redundancy mapping store having entries to map addresses of memory cells in the memory array to addresses of redundancy cells; and circuitry coupled to the redundancy array and the memory array, which executes a write operation in response to a write command, the write operation writing a data value having a selected address in the memory array whether or not there is a valid entry for the selected address in the redundancy mapping store, applying a write/verify cycle to a memory cell in the memory array having the selected address, and if the selected memory cell fails verify, then writing the data value to a redundancy cell in the redundancy array and changing or writing an entry to the redundancy mapping store to map the selected address to the redundancy cell. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of writing a memory device including a memory array having a plurality of memory cells, a redundant array having a plurality of redundancy cells, and redundancy mapping store having entries to map addresses of memory cells in the memory array to addresses of redundancy cells, the method comprising:
writing a data value having a selected address in the memory array whether or not there is a valid entry for the selected address in the redundancy mapping store, applying a write/verify cycle to a memory cell in the memory array having the selected address, and if the selected memory cell fails verify, then writing the data value to a redundancy cell in the redundancy array and changing or writing an entry to the redundancy mapping store to map the selected address to the redundancy cell. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
Specification