Browse Prior Art Database

Asynchronous Hardware Event Interrupt Handler

IP.com Disclosure Number: IPCOM000119737D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 47K

Publishing Venue

IBM

Related People

Hendershot, DR: AUTHOR [+5]

Abstract

This article describes a technique for removing a large amount of processing from an interrupt routine and letting it be done at a later time outside of the interrupt handler itself.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Asynchronous Hardware Event Interrupt Handler

      This article describes a technique for removing a large amount
of processing from an interrupt routine and letting it be done at a
later time outside of the interrupt handler itself.

      The technique disclosed herein is based on a BIOS wake-up
feature called a "One-Shot," and an asynchronous hardware event
interrupt.  The unique premise of this concept is the One-Shot
wake-up feature.  The program hooks itself into the interrupt vector
table for execution when a hardware interrupt for the specified
communications (COM) port occurs.  Due to the small processing time
available during a hardware interrupt and the fact that a single
program needs to be in control of the environment, the approach of
this disclosure was devised.

      The asynchronous event handler (AEH) of this disclosure is
shown in functional block diagram in the drawing.  When an
asynchronous hardware event interrupt occurs, the COM port management
function intercepts the hardware interrupt and processes it.  This
function then indicates to the BIOS One-Shot function that in "n"
number of timer ticks, a function call is to be made to the specified
AEH routine, within the same program or another program, to wake-up
and process the asynchronous event.  The parameters, "number of timer
ticks" (timer tick granularity is 55 milliseconds) and AEH are set
using a BIOS call.

      The program is loaded or is already loaded, such as a term...