| 摘要 |
PURPOSE:To improve the efficiency and the flexibility by causing always a microprogram interruption when an interruption request occurs and executing processings of interruption control, start of external devices, etc. with a microprogram. CONSTITUTION:When an external device 1 lights an interruption request indicator 4 in an interruption circuit 3, the microprogram interruption is generated, and the microprogram starts execution of an interruption control routine 9 in a control memory 8 of a microprogram executing circuit 7. In this interruption control routine 9, interruption request indicators 4 in the interruption circuit 3 are first read out, and a factor issuing a request out of plural factors is discriminated. The interruption request indicator 4 is reset simultaneously with this read-out. Next, an external device start routine 10 is executed in accordance with the turn-on or off states of chain processing request indicators 11 or it is discriminated whether interruption is possible or not by interruption mask indicators 12 to start the interruption processing due to machine instructions. |
