Patent ID: 7945728
Filing Date: 2011-05-17
Classification: G06F

Abstract:
1. A mass storage device, comprising: nonvolatile semiconductor memory configured to cache data, the nonvolatile semiconductor memory having a predetermined usable lifetime; a life monitor module configured to (i) determine whether the nonvolatile semiconductor memory has reached the predetermined usable lifetime and (ii) in response to the nonvolatile semiconductor memory having reached the predetermined usable lifetime, generate a first signal indicating that the nonvolatile semiconductor memory has reached the predetermined usable lifetime; a hard disk controller module configured to suspend the caching of data in the nonvolatile semiconductor memory in response to the life monitor module generating the first signal; and a static data shifting module configured to, in response to a comparison of an average number of erases across memory blocks of the nonvolatile semiconductor memory and a lowest number of erases of the memory blocks of the nonvolatile semiconductor memory, wherein the life monitor module is further configured to generate a second signal indicating that the nonvolatile semiconductor memory is once again usable to cache data based, at least in part, on the static data shifting module having stored the data within the block of memory having experienced the lowest number of erases into the block of memory having experienced the highest number of erases, and wherein the hard disk controller module unsuspends the caching of data in the nonvolatile semiconductor memory in response to the life monitor module generating the second signal.