Error characterization and mitigation for 16nm mlc nand flash memory under total ionizing dose effect
AssigneeCalifornia Institute of Technology
InventorsYue Li, Jehoshua Bruck
Life of this patent
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Abstract
A radiation hardened NAND flash memory data storage device suitable for space flight having a plurality of memory cells configured to store data values in accordance with a predetermined rank modulation scheme and a memory controller that receives a current error count from an error decoder of the data device for one or more data operations of the flash memory device and selects an operating mode for data scrubbing in accordance with the received error count and a program cycles count. Methods of operating the data storage device are also described.
Claims19
A radiation hardened NAND flash memory data storage apparatus suitable for space flight, the apparatus comprising:
- a flash memory;
- a charge pump operatively configured for page reading, page programming, and block erasure of memory cells in the flash memory;
- an error correcting code (ECC) block including program code for rank modulation coding and decoding of data to and from the flash memory;
- and
- a memory controller microcontroller configured for selecting a scrubbing mode for the flash memory from a plurality of scrubbing modes based on a current error count for one or more data operations and a program cycles count for the flash memory.
A computer implemented method of operating radiation hardened NAND flash memory data storage apparatus suitable for space flight, the method comprising:
- receiving a current error count at a memory controller microcontroller for one or more data operations and a program cycles count for a flash memory having memory cells, the current error count indicating errors detected in the flash memory;
- selecting a scrubbing mode based upon the current error count and the program cycles count;
- scrubbing the flash memory in accordance with the selected scrubbing mode;
- and
- coding and decoding data to and from the flash memory using rank modulation.
Dependencies are inferred from the claim text.