| 摘要 |
PURPOSE:To speed up the execution of a jump instruction by providing a stack register between a program counter and an RAM to change the program counter simultaneously with the transmisson of a value to the RAM. CONSTITUTION:A program counter 1 indicating a fetch address of an instruction and an RAM3 for data storage connected to the counter 1 and a data 8 constitute a sequence control circuit. A selector 9 and a stack register 10 are provide between the counter 1 of the control circuit and the RAM3 connected to the bus 8. The jump instruction is added to the selector 6 connected to the counter 1, the content of the counter 1 is transferred to the register 10 via the selector 9 at the start of the instruction. Further, a jump destination address is fed to the counter 1 at the same time, a stack pointer 5 is incremented during the execution of the instruction, the change of the counter 1 and the transmission of the modified value to the RAM3 are conducted at the same time to speed up the execution of the jump instruction. |
