| 摘要 |
PURPOSE:To improve an efficiency of the use of the whole memory by planting a first address of an instruction group that executes repetitively in the stack area of a memory for work by an indication with the stack pointer. CONSTITUTION:When a value of a program counter PC33 becomes (n), an instruction code 1 assigning the number of repetitive times of an instruction group 2 is fetched to an instruction register RG36. The instruction is decoded in a decoder 38 and outputs various kinds of controlling signals 37. One of the signals 37 sets the number of repetitive times to a loop counter 35, the other one reduces by one contents of a stackpointer SP34, and stores an address n+1 of an instruction code 4 executed in the next to the stack area of operation memory 31, and the instruction group 2 is executed successively. When a value of the counter 33, becomes n+m code 3 for the condition decision is fetched and executed. When a repetitive condition is decided to be truth, the contents of the memory 31 are made to be contents of the PC33, and when decided to be faults, and the SP34 is returned to a former state where the instruction group 2 is executed, and the instruction group 2 is executed successively. |
