| 摘要 |
<p>PURPOSE:To enable waiting time to be reduced by finding a memory region to be erased by patrol before erasure and then performing preliminary writing at a non-written part of the memory region at a preliminary writing processing part. CONSTITUTION:A patrol timer 11 sends out an interrupt request (IRQ) to a CPU 10 at a certain time interval and a patrol processing part 13 is started when it is accepted, thus enabling a flash erasure type E<2>PROM 12 to be patrolled. The, when a memory region to be erased is found before erasure, a preliminary writing processing part 14 is started immediately and preliminary writing processing is performed. This erasure is performed to a last write bit within the memory region are in write-enable state when this processing ends. In this manner, performing preliminary writing processing in dispersion eliminates the need for performing collective preliminary writing immediately before erasure and enables waiting time when performing preliminary writing to be reduced.</p> |
