Browse Prior Art Database

Single and Multiple Associated Word Selection

IP.com Disclosure Number: IPCOM000076738D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 3 page(s) / 39K

Publishing Venue

IBM

Related People

Flagg, HL: AUTHOR [+4]

Abstract

In status reporting and status inquiries in data-processing systems having multiple independently or loosely coupled units, it is desirable to be able to obtain a single status from a single unit, whether or not any given status appears in any of the loosely coupled units or all status from a given unit or a given status for multiple units. The use of multiple interconnected associative arrays facilitates selecting status words for reporting on any of the above-described bases.

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Single and Multiple Associated Word Selection

In status reporting and status inquiries in data-processing systems having multiple independently or loosely coupled units, it is desirable to be able to obtain a single status from a single unit, whether or not any given status appears in any of the loosely coupled units or all status from a given unit or a given status for multiple units. The use of multiple interconnected associative arrays facilitates selecting status words for reporting on any of the above-described bases.

Two associative arrays 10 and 12 are interconnected as shown. Array 10 is "partitioned" such that portions M and A are logically electrically OR'd together to supply signals over cable 16 to status array 12. Since a match in an associative array is usually associated with an electrical null, OR partitioning amounts to a conjunctive function, i.e., an associative selection. Keys 1 and 2 are, respectively, supplied in digital form over cables 14 and 15 to array 10. Portions A are addressing portions for selecting the device for reporting the status, while portions M are a mask for selecting a plurality of device-status words in array 10.

Logic functions are incorporated into the array 10 as defined below:

# = Mi V Ai

@ = Mi V Ai.

is a null output whenever the ith position of key 2, M, or the inverse of key 1, or in the ith position, i.e., Ai is satisfying the search argument. In a similar manner, logic function @ is satisfied whenever the ith bit of the M argument (key 2) or the ith bit of the A argument (key 1) are active. All bit positions are logically OR'd to provide word associate selection. From the above, it can be readily seen that if the ith bit of the M argument is a 1 the state of the corresponding ith bit of the A argument is ignored. For example, if M is all 0's, then a single-device status will be selected in accordance with the A argument or address. If the lowest order position of the M argument is a binary 1. then that portio...