Flash memory for storage devices, has control circuit detecting defects arising in memory block, and select circuit picking a redundancy memory block when defective information on defective memory block is detected

摘要

The device has a memory array (10) with two blocks of memory cells for a high and a low data rewrite frequency. A redundancy memory block (13) serves as a substitute for a defective block in the first memory block, and a control circuit detects the defects arising in the first memory block. A select circuit (20) picks a redundancy memory block when defective information on the block is detected.