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X Type Instructions

IP.com Disclosure Number: IPCOM000077982D
Original Publication Date: 1972-Oct-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Lampe, HH: AUTHOR [+2]

Abstract

This type of instruction permits theological processing (OR, AND, XOR, ADD, MOVE, COMPARE) of nonsequential operand bytes with one single instruction.

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X Type Instructions

This type of instruction permits theological processing (OR, AND, XOR, ADD, MOVE, COMPARE) of nonsequential operand bytes with one single instruction.

Formerly, the logical processing of nonsequential bytes, due to the sequential selection of operand bytes, had been possible through sequences of several instructions only, which necessitated considerable storage capacity.

The X-Type instructions use address displacement tables (TAB) for defining nonsequential bytes within the operands. These displacement tables are either subordinated as auxiliary instructions to the X-Type instructions, or they are called as auxiliary operands within the instructions.

The displacement tables contain the positive or negative addition constants, by which the addresses of the nonsequential operand bytes differ from the operand address per se (e.g. +1phi, +132, -2, -7, etc.j. For the logical combination there are two possibilities: 1) logical combination of two operands with nonsequential bytes (two displacement tables). 2) logical combination of a sequential operand with an operand with nonsequential bytes (one displacement table).

The second alternative, not shown in the figure, permits, provided the sequential operand is selected via an address register (indirect addressing), the modification of the address of the sequential operand during the execution by means of an addition constant within the X-Type instruction, so that the bytes of the sequential operand c...