Signature detecting method and apparatus for isolating source of correctable errors

• US 5,220,567 A
• Filed: 12/26/1991
• Issued: 06/15/1993
• Est. Priority Date: 12/26/1991
• Status: Expired due to Fees

• Current Assignee: Amdahl Corporation (Fujitsu Limited)
• Original Assignee: Amdahl Corporation (Fujitsu Limited)
• Inventors: Dooley, Dave, Zalewski, George, Crater, Michael R., Satterlee, Chris
• Primary Examiner(s): Canney, Vincent P.
• Application Number:
  US07/814,275
• Time in Patent Office: 537 Days
• Field of Search: 371/5.1, 371/16.1, 371/16.5, 371/19, 371/23, 371/25.1, 371/26, 371/29.1, 371/29.5
• US Class Current: 714/704
• CPC Class Codes: G06F 11/2205 using arrangements specific to the hardware being tested

Abstract

The invention provides a method and apparatus for generating a signature signal which indicates a probable location for an error-causing mechanism within a digital system, where the digital system has control-signal and data-signal carrying busses and error detection means for detecting error conditions in the signals carried by those busses. The signature generating method comprises the steps of: counting the total number of errors detected by the error detection means during a signature generating run; and counting the number of errors detected by the error detection means during a signature generating run where those errors were accompanied by the presence of accompanying signals on the signal-carrying busses, the accompanying signals being ones which belong to a predefined subset of all signals appearing on the system signal-carrying busses.

Claims

1. A signature generating apparatus for generating a signature signal which indicates a probable location for an error-causing mechanism within a digital system, where the digital system has control-signal and data-signal carrying busses and error detection means for detecting error conditions in the signals carried by those busses, the signature generating apparatus comprising:

first counter means, coupled to the error detection means, for counting the total number of errors detected by the error detection means during a signature generating run;

second counter means, coupled to the error detection means and the signal carrying busses of the system, for counting the number of errors detected by the error detection means during a signature generating run where those errors were accompanied by the presence of accompanying signals on the signal-carrying busses, the accompanying signals being ones which belong to a predefined subset of all signals appearing on the system signal-carrying busses.

2. A method for generating a signature signal which indicates a probable location for an error-causing mechanism within a digital system, where the digital system has control-signal and data-signal carrying busses and error detection means for detecting error conditions in the signals carried by those busses, the signature generating method comprising the steps of:

counting the total number of errors detected by the error detection means during a signature generating run; and

counting the number of errors detected by the error detection means during a signature generating run where those errors were accompanied by the presence of accompanying signals on the signal-carrying busses, the accompanying signals being ones which belong to a predefined subset of all signals appearing on the system signal-carrying busses.