Abstract: Programming a reference voltage in a reference cell of a charge-based memory to a level that will maximize the predicted operational life of the memory, based on the application-specific predicted usage profile of the memory and the effects of that usage profile on the leakage curves of the various memory states. The different states of a memory cell may have different leakage rates, based on operational and environmental considerations, causing the cell to fail prematurely in one state, while having significant remaining life in the other state(s). The operational life of the memory can be increased by adjusting the reference threshold voltage so that the faster-leaking sate will last longer before failure occurs. Maximum operational life can be achieved by setting the reference voltage to maximize the predicted time-to-failure of the state with the shortest predicted time-to-failure.

Abstract: Programming a reference voltage in a reference cell of a charge-based memory to a level that will maximize the predicted operational life of the memory, based on the application-specific predicted usage profile of the memory and the effects of that usage profile on the leakage curves of the various memory states. The different states of a memory cell may have different leakage rates, based on operational and environmental considerations, causing the cell to fail prematurely in one state, while having significant remaining life the other state(s). The operational life of the memory can be increased by adjusting the reference threshold voltage so that the faster-leaking state will last longer before failure occurs. Maximum operational life can be achieved by setting the reference voltage to maximize the predicted time-to-failure of the state with the shortest predicted time-to-failure.

Abstract: An embodiment of the invention is directed to a method of operating a flash memory, which includes discharging at least one local wordline of an unselected block of flash memory cells during an interval in which a selected set of flash memory cells are being conditioned, such that the at least one local wordline does not develop a charge that is sufficient to corrupt the data stored in the unselected block.