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Browse Prior Art Database

Time Division Multiplexed Non-vectored Interrupt

IP.com Disclosure Number: IPCOM000109357D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 2 page(s) / 80K

Publishing Venue

IBM

Related People

Andrews, LP: AUTHOR [+5]

Abstract

This article describes a method and hardware enablement for use in microprocessors which allows non-vectored interrupts to be used instead of vectored interrupts.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Time Division Multiplexed Non-vectored Interrupt

       This article describes a method and hardware enablement
for use in microprocessors which allows non-vectored interrupts to be
used instead of vectored interrupts.

      Microprocessors which have non-vectored interrupts suffer from
having a unique auto-vector to handle an interrupt which may
originate from several sources.  Vectored interrupts allow greater
flexibility by using different vectors to handle several devices and
their requirements.

      When interfacing to a microprocessor-based controller with few
vectors available on vectored interrupts and the use of non-vectored
interrupts are available, the method disclosed herein allows the
non-vectored interrupts to be used instead of vectored interrupts.

      The time division multiplexed non-vectored interrupt (TDMNVI)
scheme disclosed herein is shown in Fig. 1.  The device presenting an
interrupt contains a register with a vector and the physical address
of the device.  Each device contains a counter which is clocked by
the system clock and is reset whenever the microprocessor-based
controller issues a synchronization (SYNC) signal.  Each device is
assigned a time slot according to its physical address.  Whenever the
contents of the counter match the physical address of a device, the
device is allowed to interrupt.  Since the physical addresses are
unique there can only be one device requesting an interrupt at any
given time.  Before a device issues an inter...