An At-Speed Test Technique for High-Speed High-order Adder by a 6.4-GHz 64-bit Domino Adder Example

This work presents the first case of using the pseudoexhaustive testing (PET) for high-speed high-order (>;32 -bit) adders. It is shown that all single stack-at faults are detected by a pseudoexhaustive test set of 54 K patterns, compared to 2^64×2 patterns in the past. Also, all transition faults are detected by a pseudoexhaustive test set of 13 M patterns, compared to 2^64×4 patterns in the past. In addition, with a programmable-delay clock generated from DLL, the adder latency is accurately measured. The proposed technique was validated by an example of a 6.4-GHz domino adder with 181 ps latency in a 90-nm CMOS technology. With the latency measurement, speed binning of high performance CPUs is now possible.