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Computer Instruction Set Expansion Using a Priming Operation

IP.com Disclosure Number: IPCOM000085303D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Miracle, G: AUTHOR

Abstract

A computer instruction set can be expanded by executing a single "priming" instruction immediately before an instruction to be modified, affecting only the execution of that one instruction. The priming instruction does not necessarily have to use a new operation code, but can be any existing operation code with a new definition added to a field of the instruction (other than the operation code field).

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Computer Instruction Set Expansion Using a Priming Operation

A computer instruction set can be expanded by executing a single "priming" instruction immediately before an instruction to be modified, affecting only the execution of that one instruction. The priming instruction does not necessarily have to use a new operation code, but can be any existing operation code with a new definition added to a field of the instruction (other than the operation code field).

The priming instruction can be designed to cause modification of the following instruction in one or more ways, or not at all. This permits the program to dynamically alter priming instructions, thus causing the following instructions to execute either normally or in various different ways.

Some instructions could always execute normally, regardless of the presence of a priming instruction. This would allow dynamic alteration of the instruction stream to make a priming instruction either functional or nonfunctional.

A particular priming instruction could also set a new mode of operation affecting all subsequent instructions, until another priming instruction was executed.

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