| 摘要 |
PURPOSE:To control a microprogram in an excellent way, by providing the 1st and the 2nd control memories, the 1st and the 2nd address switching sections, an adder and a control section and the like, and constituting the system so that the start address of the 2nd control memory is used selectively. CONSTITUTION:Control memories 2, 11, address switching sections 13, 15, control memory address register 4, adder 5 and a control section 14 and the like are provided. A memory 11 is provided with the 1st and the 2nd specific field. The 1st specific field stores a required processing routine, the 2nd specific field discriminates the content of the 1st specific field so as to use selectively the start address of the memory 11. Then, the microprogram control is attained without increasing the capacity in the direction of bit of the memory 11 and without increasing the capacity of the microprogram. |
