| 摘要 |
PURPOSE:To change easily and efficiently microprogram by controlling an arithmetic circuit, which converts relative addresses where the microprogram is changed to absolute addresses, in accordance with change data corresponding to absolute addresses. CONSTITUTION:A main storage 2 is provided with a microprogram change instruction storage area 5 and a microprogram storage area 6, and an operating circuit 3 which reads out and executes successively the program and a control storage 4 where the microprogram is stored are provided in a processor 1, and the area 5 consists of an instruction code area 51, an address area 52, and a data area 53. A'n relative address of the microprogram is stored in the area 52, and change data is stored in the area 53, and one base value of absolute addresses is accessed from a table 9 in accordance with upper two bits of the relative address, and the address obtained by adding this base value to the value of low-order bits of the relative address by an adder 10 is defined as the absolute address in the main storage 2. |
