Browse Prior Art Database

Shared Decode for Improved Serviceability

IP.com Disclosure Number: IPCOM000076780D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Frassetto, HE: AUTHOR [+3]

Abstract

In microprogrammed machines with read/write storage, one area which presents difficulties in diagnosing failures is the logic used to load the controlling microprogram. Any type of failure in this logic, which prevents loading of programs, will also prevent the loading of any diagnostics to aid in servicing the problem.

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Shared Decode for Improved Serviceability

In microprogrammed machines with read/write storage, one area which presents difficulties in diagnosing failures is the logic used to load the controlling microprogram. Any type of failure in this logic, which prevents loading of programs, will also prevent the loading of any diagnostics to aid in servicing the problem.

The most direct way to manually diagnose is to use the customer engineer (CE) console from which manual storage and displays of pertinent information are available. However, since the CE console is a unique entry to the data flow of the machine, it may not accurately point to the problem logic and may indeed mask some failures.

To overcome these problems, a common path is provided for the microprogram input and the customer engineering panel inputs to facilitate CE failure analysis.

Data from IPL file 10 is deserialized by serial-to-parallel converter 18 which provides the file data in parallel to registers 22 and 24, as well as other registers and compare circuits in the machine.

The CE/file command register 22 is loaded from either of two sources. It is loaded from deserializer 18 under the control of IPL file 10, or it is loaded from the CE function switches when appropriate switches are depressed on the CE Panel 12.

The command register is decoded to determine the function to be performed either under file control or CE control. A two-bit section of the command register 22 duplicates the function of th...