Estimating the relative single stuck-at fault coverage of test sets for a combinational logic block from its functional description

When the gate-level description of a logic block is unknown, it may become necessary to estimate the gate-level stuck-at fault coverage of a test set for the block by using a fault coverage metric that does not require simulation of gate-level faults. We propose such a metric based on stuck-at faults on primary inputs of the block. We show that the proposed metric is accurate in predicting the relative gate-level stuck-at fault coverage of different test sets.