Data refresh in non-volatile memory

摘要

A method of reducing read errors in a non-volatile memory device that result from bit-line or word-line disturb conditions generated by erase operations includes selecting a subset of a memory array for refresh after each erase operation. A pointer to the refresh target section is updated as part of the method to direct the refresh operation to the appropriate subset of the memory array. Refresh may be performed subsequent to an erase operation or concurrently therewith. By distributing the time consumed by refresh operations over many erase operations so the relative refresh time for any one erase becomes small.

主权项

1. A method of distributing across multiple erase operations, refreshing of content of plurality of groups of non-volatile memory cells in an integrated circuit, comprising:
providing one pointer, the one pointer associated with each of the plurality of groups of non-volatile memory cells; detecting an erase operation directed to a first group of the plurality of groups of the non-volatile memory cells; refreshing a second group of the plurality of groups of the non-volatile memory cells, the second group of the plurality of groups specified by a first state of the one pointer; and operating the one pointer such that the one pointer has a second state; wherein the second group of the plurality of groups of the non-volatile memory cells is less than all of the plurality of groups of the non-volatile memory cells.