First level hold: a novel low-overhead delay fault testing technique

This paper presents a novel delay fault testing technique, which can be used as an alternative to the enhanced scan based delay fault testing, with significantly less design overhead. Instead of using an extra latch as in the enhanced scan method, we propose using supply gating at the first level of logic gates to hold the state of the combinational circuit. Experimental results on a set of ISCAS89 benchmarks show an average reduction of 27% in area overhead with an average improvement of 62% in delay overhead and 87% in power overhead during normal mode of operation, compared to the enhanced scan implementation.