Incremental test pattern generation

Abstract

Discusses a test pattern generation (TPG) algorithm for single stuck-at faults in combinational logic circuits. Current TPG systems generate a test vector for fault F/sub i+1/ independently of the computation previously done for faults F/sub 1/, F/sub 2/, . . ., F/sub i/. The algorithm ITPG, generates a test vector for fault F/sub i+1/ by starting with (inheriting) the test vector for fault F/sub i/. A new test vector is generated from inherited values by gradually changing the inherited values. The inherited values may partially activate a fault and propagate the fault signal. Normally, this reduces the number of decision steps and backtracks in the second search. Experimental results for well-known benchmark circuits show that ITPG is very efficient with a small backtrack limit; in combination with other algorithms, it is very efficient for arbitrary backtrack limits.<>