Browse Prior Art Database

Interrupt Check Routine

IP.com Disclosure Number: IPCOM000051906D
Original Publication Date: 1981-Mar-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Hsieh, DM: AUTHOR

Abstract

This system provides a routine for carrying out an interrupt between a control tool, such as a printer, and the controlling processor for carrying out interrupts in the printer which are generated by the processor. The primary purpose of the routine is to distinguish a true interrupt from noise, which is much shorter in duration. The problem is resolved by adding a status check in the interrupt routine.

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Interrupt Check Routine

This system provides a routine for carrying out an interrupt between a control tool, such as a printer, and the controlling processor for carrying out interrupts in the printer which are generated by the processor. The primary purpose of the routine is to distinguish a true interrupt from noise, which is much shorter in duration. The problem is resolved by adding a status check in the interrupt routine.

With reference to the figure, in accordance with the routine when an interrupt is to be generated by the processor for the printer, the interrupt signal which is generated by interface 10 for processor 11 along line 12 is also sent along line 13 and stored at a particular bit position 14 in a designated status byte 15. After a short interval which is sufficient for any stray noise to have subsided, the particular status bit 14 is again sensed in order to determine if it is still on. If it is still on, it would be indicative of the continued presence of an interrupt signal. Thus, when the bit is still on, the system recognizes an interrupt and the processor continues to carry out the interrupt routine with respect to printer 16.

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