Browse Prior Art Database

Array for Tracing System Control Information

IP.com Disclosure Number: IPCOM000060836D
Original Publication Date: 1986-May-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cheng, FM: AUTHOR [+4]

Abstract

An array for tracing system control information usually has a limited number of stages. In many cases the trace mechanism is stopped long after the failure has occurred. By that time, pertinent data in the array has been overwritten with idle data. To assure that the trace array will contain the pertinent data, logic under control of a mask register controls the trace address counter. This mask register specifies which operation is to be traced. As long as the selected operation is in process, the trace array address counter advances; otherwise, the trace address advance is stopped, and a counter counts the number of idle cycles that have occurred before the trace mechanism is stopped.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Array for Tracing System Control Information

An array for tracing system control information usually has a limited number of stages. In many cases the trace mechanism is stopped long after the failure has occurred. By that time, pertinent data in the array has been overwritten with idle data. To assure that the trace array will contain the pertinent data, logic under control of a mask register controls the trace address counter. This mask register specifies which operation is to be traced. As long as the selected operation is in process, the trace array address counter advances; otherwise, the trace address advance is stopped, and a counter counts the number of idle cycles that have occurred before the trace mechanism is stopped. The counter is allowed to run to its maximum value and then stops advancing, indicating that at least that many cycles of non- traced time have occurred since the failure and before the trace mechanism is stopped.

1