US Government As Represented by the Secretary of the Army

Raytheon Company

Jan S Herman

Gerald P Richards

H Frank Howes

James K Mathewes, Jr

Peter A Morrison

C W Eifrig

Charles O Schulz

Apparatus and method for providing programmable fault insertion circuitry in a large scale integrated (LSI) circuit device thereby eliminating the need for external switches or relays to create faults. A fault parameter word is stored in a register and the outputs of the register are decoded to select the fault condition to be inserted by an interfacing circuit to the logic being tested. Test vectors and the fault parameter word are generated by a controller coupled to the integrated circuit and a test response from the integrated circuit is examined by the controller.

LSI fault insertion

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.

Method and apparatus for signaling on-line failure detection

Growing community of inventors

Holliston, MA, United States of America

Jan S Herman