Gerald Richards

US Patent:

45396825, Sep 3, 1985

Filed:

Apr 11, 1983

Appl. No.:

6/484107

Inventors:

Jan S. Herman - Holliston MA
Peter A. Morrison - Framingham MA
Gerald P. Richards - Framingham MA

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G06F 1100

US Classification:

371 15

Abstract:

Method and apparatus permitting a multi-module digital system, such as a puter, having built-in test hardware associated with each module, including a plurality of signal processing units to communicate over two wire circuitry not only the existence of a failure of a particular module, but also its causality. This is accomplished by means of a four state signaling circuit interposed between each signal processing unit of a particular module and a module built-in test circuit which operates once an error output is reported by a signal processing unit to provide a further four state indication of the details of the failure.