Reliability of space image recorder based on NAND flash memory

For the unreliable data storage problem caused by bad blocks and single event upsets for the NAND flash memory in a space camera, this paper explores a bad block management strategy and an error correction algorithm. Firstly, the bad block management strategy based on parallel double-traverse mechanism was proposed by analyzing the characteristics of structure and operation for the NAND flash memory, the design ideas of the double traverse mechanism were described and its effectiveness was analyzed. Then, the error correction algorithm based on the shortened code RS (246, 240) and RS (134, 128) in the field GF (2 ⁸) was proposed, and the encode/decode algorithm and corresponding circuits were given. Finally, the verification experiments on an image storage platform in the prototype machine for a space multi-spectral camera were carried out. The experimental results show that the bad block management strategy can fast and reliably dispose the bad block events, and the algorithm can identify the bad blocks in one system clock period. The error correction algorithm can correct 27 B error within the 2 KB/page with a encoder speed of 72.53 MBps and a decoder speed of 54.26 MBps. Proposed stratege effectively solve the problem of unreliable recording data in the NAND flash memory.