| 摘要 |
PURPOSE:To constitute simply a program by comparing the content of a program counter with a return address of a subroutine and applying the control to return the content of a stack circuit to the program counter when they are coincident. CONSTITUTION:The content of the program counter 1 reading an instruction address of the processor is stored in a stack circuit 2 at subroutine call. The return address of the subroutine is stored in the register 8, the content of the counter 1 and the content of the register 8 are compared by a comparator 4 and when the coincidence of both is detected, the comparator 4 outputs a control signal to the control circuit 5. The control circuit 5 applies control to return the content of the circuit 2 to the counter 1. Thus, a conditional branch instruction and a return instruction used conventionally are omitted to constitute simply the program and the processing time is reduced.
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