| 摘要 |
<p>PURPOSE:To efficiently clear an operation memory in a short time by providing a clear circuit which clears contents of the operation memory by the instruction of a control CPU. CONSTITUTION:An operation memory 4 temporarily holds the value on the way of operation of a computing element 3 or holds the value for a long time. A clear circuit 5 clears contents of the operation memory 4 simultaneously with rewrite of contents of a program memory 2 due to a control CPU 1, and the end of clear is reported to the control CPU 1 when clear is terminated. By this constitution, rewrite of the program memory and clearing of the operation memory are simultaneously performed in parallel. Therefore, it does not take a long time to rewrite the program memory, and the rewrite time is used for clearing of the operation memory. Thus, the operation memory is efficiently cleared in a short time.</p> |
