Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-05
This article provides a technique for testing microprocessors with built-in test routines. An input control line called Diagnostic Enable/Disable Request and an output control line called Self-Check Complete are manipulated and, as a result, the processor is forced to perform the sequence of tests in its repertoire. As a result, the microprocessor is tested at operational speed as opposed to the use of tester generated input frequencies using a generic pattern set at non- operational speed. Referring to the figure, the two control lines allow a card tester (not shown) to evaluate the operational status of the microprocessor unit containing a processor, ROS (read-only storage), RAM (random- access memory) and I/O support circuitry.