| 摘要 |
After erasing a plurality of non-volatile storage elements, a soft programming process is performed to tighten the erase threshold distribution for the non-volatile storage elements. During the soft programming process, the system identifies the number of programming pulses needed for a first set of the non-volatile storage elements to complete the soft programming and the number of programming pulses needed for the all but a last set of non-volatile storage elements to complete soft programming. These two numbers are used to characterize the threshold distribution of the non-volatile storage elements. This characterization of the threshold distribution and the program pulse step size are used to limit the number of verify pulses used during subsequent programming.
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