| 摘要 |
PURPOSE:To write a data of a start address of an interruption processing program in a program counter, by only adding a priority setting circuit to an initial resetting circuit of the program counter. CONSTITUTION:In an interruption processing circuit of a microprocessor, in case a start address of an internal or external interruption processing program is decided in advance, a priority setting circuit is provided in an initial resetting circuit of a program counter 2. The program counter 2 is formed by arraying an F/F in parallel in 12 stages, and when the program is initialized and is started from an address ''0'', a reset signal 4 is made an active state. In case of the internal interruption and the external interruption, a set signal 5 and 6 are made an active state, respectively. In this way, when the reset signal 4 and said set signal 5 or 6 become an active state simultaneously, said set signal takes a priority, and contents of the program counter 2 become contents of a start address of each interruption program. |
