Architecture and method for testing VLSI processors

Claim 1

Apparatus for testing a processor on a VLSI chip having a data path, a memory, and a control section, comprising: a data monitor on said chip, wherein said data monitor can be selected to operate in a normal mode or a test mode, and wherein said data monitor when operating in test mode receives and compresses signals from the data path and develops a signature indicative of success or failure during test; a control monitor on said chip, wherein said control monitor can be selected to operate in a normal mode or test mode, wherein said control monitor when operating in the normal mode receives and compresses signals from the control section after such signals pass through the data path to develop a signature indicative of success or failure during test, and wherein said control monitor when operating in the test mode can supply control signals to the control section in order to test desired modes of operation, and further wherein said control monitor and said data monitor can both operate in test mode simultaneously; and a test pattern generator for generating test patterns for application to said data and control monitors, wherein the test patterns, when so applied, cause the functions of the processor to be exercised and signals to be produced which are coupled to said data and control monitors, wherein the signatures indicative of success of failure during test are generated after the test patterns are generated.