| 摘要 |
<p>PURPOSE:To change only a desired bit through a simple logical operation without storing an output state on a program, by allocating the address of an output port to the same address as a data memory. CONSTITUTION:A microprocessor system comprises a program area 100 (corresponding to a program memory 2) where the executing procedure of a microprocessor 1 is described, a data area 101 (corresponding to a data memory 3) where the middle result of an operation is stored, and an output port area 102. This area 102 shares the area 101. Then the data is written to the same address on the area 101 as soon as the data is delivered to the area 102 from the processor 1. While the same data in the data memory 101 is read instead of a case where the data of the area 102 is read by the processor 1.</p> |
