A flash controller for managing at least one MLC non-volatile memory module and at least one SLC non-volatile memory module. The flash controller is adapted to determine if a range of addresses listed by an entry and mapped to said at least one MLC nonvolatile memory module fails a data integrity test. In the event of such a failure, the controller remaps said entry to an equivalent range of addresses of said at least one SLC non-volatile memory module. The flash controller is further adapted to determine which of the blocks in the MIX and SLC nonvolatile memory modules are accessed most frequently and allocating those blocks that receive frequent writes to the SLC non-volatile memory module and those blocks that receive infrequent writes to the MLC non-volatile memory module.