Patent ID: 9201717
Filing Date: 2015-12-01
Classification: G06F,G11C

Abstract:
1. A memory system comprising: a nonvolatile memory including a plurality of blocks; and a controller configured to count a number of bad blocks in the nonvolatile memory, wherein, in a case that the number of counted bad blocks in the nonvolatile memory has reached a first threshold, a warning indication is issued, in a case that the number of counted bad blocks in the nonvolatile memory has reached a second threshold, a data write operation to the nonvolatile memory is prohibited, the first threshold being less than the second threshold, wherein, immediately after power is turned on and before the memory system is started, the controller inspects an internal state of the controller and refers to the number of counted bad blocks in the nonvolatile memory, and in a case that the number of counted bad blocks in the nonvolatile memory has reached the second threshold, the controller controls the nonvolatile memory so that the nonvolatile memory is started in a read only mode.