Patent ID: 7464306

Claim:
A nonvolatile memory system comprising: nonvolatile memory organized into blocks, one or more of which are designated as spare blocks and one or more of which may be defective at the time of manufacturing of the nonvolatile memory; and a controller device coupled to the nonvolatile memory for measuring the health status of the nonvolatile memory by determining a number of growing defects on an on-going basis and determining a total number of remaining spare blocks at the time of the measurement of the health status by subtracting the number of defects at the time of the measurement of the health status from a total number of spare blocks within the nonvolatile memory that are initially reserved as spare blocks, wherein the total number of remaining spare blocks at the time of the measurement of the health status is indicative of the health status of the nonvolatile memory; wherein the controller is configured to output a signal indicative of the total number of remaining spare blocks at the time of the measurement of the health status.