Patent ID: 7437602

Claim:
A memory card having a function to notify a host of a memory capacity of user-accessible area of said memory card, said memory card comprising: a nonvolatile semiconductor memory having a plurality of nonvolatile memory cells and being capable of storing data; and a controller to provide instructions to operate said nonvolatile semiconductor memory based on externally issued commands, wherein said controller registers, as a faulty block, any block of said nonvolatile memory cells determined to be faulty in writing at a time of writing data into said nonvolatile semiconductor memory, wherein said controller executes, after registering a block determined to be faulty, a determination test to perform at least one of write and read comparison on said block determined to be faulty, and if said block is found to be normal based on said determination test, said controller determines said block to be a good block for re-registering said block as a normal block, wherein said controller executes said determination test in response to a dedicated command issued from outside or in response to a power on reset sequence, wherein, after said determined faulty block is re-registered as a normal block, if a number of normal blocks in a valid data area is not more than a prescribed value, said controller reduces said memory capacity of said user-accessible area, secures a block in said valid data area as a standby area, and alters said memory capacity of said user-accessible area stored in a system area of said nonvolatile semiconductor memory to a reduced memory capacity, and wherein said controller executes said power on reset sequence after altering said memory capacity of said user-accessible area stored in said system area of said nonvolatile semiconductor memory to said reduced memory capacity.