| 摘要 |
<p>PURPOSE:To compensate the lowering of reliability due to a large number of rewriting by incorporating a memory rewriting-number memory means and automatically refreshing contents every time memories exceed some number of rewriting. CONSTITUTION:When an address signal is inputted to an address input circuit 12, an arbitrary cell on a memory matrix 11 can be selected through an address buffer latch circuit 13, an X decoder 14 and a Y decoder 15. A data is inputted and outputted through a data input/output circuit 16 and an input/output buffer latch circuit 17. A nonvolatile memory counter 21 previously memorizes the number of rewriting every time memories are rewritten, and refreshes memory contents in the memory through a refresh control circuit 22 every time the number of rewriting exceeds set number. A memory cell, the threshold thereof varies by use for a prolonged time, can be returned forcibly to the normal state of 1 or 0, and malfunction can be prevented.</p> |
