Test principle and key point of SSD Power-off Protection
Considering the SSD must be based on FTL to realize the data transfer between logical address and physical address, if there happens abnormal power-off in case of normal operation (read/ program/erase), it may lead the loss of mapping table which has not finished updating and resulting in the SSD failed to be detected by host. Meanwhile, to improve the read/write performance, SDRAM normally adopted as buffer on SSD board.The abnormal power-off also can cause the loss of data or updated mapping table which have not been written into NAND Flash from SDRAM. Failure problems caused by abnormal power-off 1. SSD cannot be detected by OS once sudden power-off, it only be reusable after re-build mapping table or replanting. 2. Mass new bad block generated after repeatedly abnormal power-off. The mechanism of new bad block generated is: when SSD cannot successfully read/ program or erase some blocks, such blocks would be marked as bad block. However, they are not real bad blocks, but a ...