| 摘要 |
PURPOSE: A device for extending an interrupt of a computer system is provided to enable boards to share one interrupt and recognize the interrupt by a CPU in a polling method. CONSTITUTION: An interrupt request element(40) requests an interrupt to a CPU. A driver(41) receives the interrupt request from the interrupt request element(40) and asserts an interrupt request signal(int-rq) of a system bus. If a board 'n' is stuck in a slot, a slot inherent number storing unit sets the slot number. A buffer(43) receives and stores the slot inherent number set through a DIP(dual inline package) switch(42). If an interrupt request exists from the interrupt request element(40), the buffer(43) allocates and stores one bit. In addition, if an output terminal is enabled, the buffer(43) outputs the stored data to a data bus of a system bus. A decoder(44) receives an address bus and an I/O read signal of the system bus. The decoder(44) compares a set slot number of the DIP switch(42) with an address on condition that the I/O read signal is enabled. If the set slot number of the DIP switch(42) is accorded with the address, the decoder(44) enables the output terminal of the buffer(43), enables a clear signal of the driver(41) and clears an interrupt request signal being output to the system bus from the driver(41).
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