Browse Prior Art Database

Independent Interrupt Triggering by Timer Signal

IP.com Disclosure Number: IPCOM000107783D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 33K

Publishing Venue

IBM

Related People

Muerle, U: AUTHOR

Abstract

A programmable logic device generates an independent interrupt request in response to a normal timer output signal.

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This is the abbreviated version, containing approximately 100% of the total text.

Independent Interrupt Triggering by Timer Signal

       A programmable logic device generates an independent
interrupt request in response to a normal timer output signal.

      Computer systems often use peripheral timer circuits for
various functions, such as baud rate generation or wait loops.
Interrupt- driven systems normally assign only one interrupt level to
the peripheral timer circuit, whereas system users frequently require
independent interrupt levels for using two or more functions kept on
the peripheral device.

      The figure shows the typical behaviour for a special function.
After reset, the timer is conditioned and starts counting.  The
counter is periodically stopped and reset during normal processing.
During count-down, the timer output signal changes its polarity.
This is detected by a programmable logic device which manages the
interrrupt request and interrupt acknowledge activities itself and is
therefore user-transparent.  The processor changes to the interrupt
state and proceeds with interrupt service.  At the end of interrupt
service, the timer is stopped and reinitialized to continue at task
level.

      Independent interrupt triggering may also be used for other
timer applications.