| 摘要 |
<p>PURPOSE:To provide a highly reliable writing and reading method by using a check bit as an electrostatic charge injection type and invertionally writing the contents of the program data bits when the bits for injecting charge to a gate exceeds a half of the contents of the program data bits, and when the bits less than a half, reversely processing. CONSTITUTION:The number of '0' bits in the program data obtained from an 8-bit microprocessor or the like is counted up. When the number of '0' bits exceeds a half of the number of program data bits, the data obtained by inverting the ordinary program data are written in an EPROM together with a check bit '0'. Next, the written-in data processed as above are written-in to the EPROM. The programs data are read out from the EPROM, and when the check bit is '0', the contents of the read program data are inverted so as to be used.</p> |
