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公开(公告)号:GB2279162B
公开(公告)日:1997-11-19
申请号:GB9312272
申请日:1993-06-15
Applicant: IBM
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公开(公告)号:GB2279162A
公开(公告)日:1994-12-21
申请号:GB9312272
申请日:1993-06-15
Applicant: IBM
Inventor: HENRY MICHAEL DAVID , LEAVER DAVID , WRIGHT-BOULTON NEIL , HARE MARK WILLIAM , JACKSON FREDERICK SAMUEL
Abstract: An interrupt-driven processor system comprising a processor 10 connected via a plurality of processor input and output lines to an input means 20 in the form of a keypad or keyboard. Actuation of one of the keys of the input means generates an interrupt signal on one of the input lines which invokes an interrupt service routine in the processor. In accordance with the invention, a secondary interrupt source can be attached to each of the input lines with the interrupt service routine being designed to discriminate between an interrupt signal generated by actuation of a key and an interrupt signal generated by a secondary source. Using this technique, further interrupts can be added to an off-the-shelf processor including keypad interrupts without the need for additional interrupt controlling hardware. Furthermore, a custom-built microprocessor can be designed with fewer interrupt pins.
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