| 摘要 |
<p>PURPOSE:To rewrite in a short time by writing information in a temporary storing means during the erasing period of an EEPROM, and prohibiting the writing in the temporary storing means during the write time following the erasing period. CONSTITUTION:When a rewrite start input (a) is impressed, a control output from a rewrite control means 11 is supplied to an input buffer 10, a row decoder 5, and a column decoder 6, and the EEPROM of nonvolatile memory cell array 4 is erased and at the same time the write information is written in the temporary storing means 7 through the buffer 10 that permits the input. After allowing the erasing action to be automatically ended, the control means 11 supplies an inhibiting signal to the buffer 10 to prohibit the writing in the means 7, and at the same time starts the rewriting of the information written in the means 7 to a ROM 4. By such control timing, the writing period to the means 7 does not need to be independently provided. As a result, the rewriting of the EEPROM can be executed within a short time.</p> |
