| 摘要 |
PURPOSE:To prolong the life of the entire memory by automatically updating the check sum address in case of the prescribed number of data updatings in the identical check sum address. CONSTITUTION:A means 2 detecting the generation of the check sum address to write the check sum and means 4 and 5 counting the generation of this detection output and updating the contents of output when the number of this generations amounts to the number determined in advance, are provided, and the contents of this output is turned to a new check sum address. For example, the address detection of the check sum address detection circuit 2 amounts to 10,000, the output of a counter 4 changes to update the contents of the output, and a signal 41 after this updating as a new check sum address is provided as the check sum write address of an E<2>PROM 6 through a selector 5 after this updating. Thus, the life of the memory of the E<2>PROM 6 can be prolonged. |
