| 摘要 |
<p>PURPOSE:To prolong the service life of a P-ROOM by using one specific address of each row of an nXn-bit ROM as an address area, shifting addresses every time data is written, and using the entire data area uniformly. CONSTITUTION:The most significant digit bits of respective columns of the nXn-bit ROM are used for an address signal and every time data is written, flags are set to 1 and the data is written forward in columns whose flags are zero. Then when all flags are set to 1, a return to the 1st column is made and while the flags are set to 0, the data is written in columns whose flags are 1 similarly. Consequently, the entire area of storage capacity is used, there is no local fatigue deterioration caused, and the life can be prolonged.</p> |
