IDENTIFICATION OF FAULTS IN DATA PATHS AND FUNCTIONAL UNITS OF A CENTRAL PROCESSING UNIT BY SYSTEMATIC EXECUTION OF TEST INSTRUCTIONS

A systematically structured diagnostic for detecting, isolating, analyzing and reporting problems or faults in a central processing unit. The diagnostic causes the central processing unit to execute instructions, the instructions being selected such that the central processing unit, in executing the instructions, must use every data path and functional unit therein. Errors caused by particular instructions are correlated with the functional units or datapaths used by those instructions, to produce a list of possibly faulty datapaths and functional units. Test procedures, specifically designed to the possibly faulty datapaths and functional units, are then applied to the central processing unit to isolate which of the possibly faulty data paths or functional units are in fact faulty, which are then reported. The instructions, test procedures and other information used by the diagnostic are stored in databases, so that the diagnostic has a modular and data-driven structure which permits evolution of the diagnostic over time as the central processing unit layout changes and the diagnostic is upgraded to provide higher levels of fault-detection functionality.