Testing of zipper CMOS logic circuits

Zipper CMOS is a dynamic CMOS circuit technique which also provides protection against instability and charge-sharing problems; this is achieved by using a special driver circuit. A method for testing of zipper CMOS circuits is presented. The testing is done with the help of a single stuck-at-fault test set derived from the gate-level model of the circuit in which the vectors have to be properly arranged and sometimes also repeated. This test set detects not just all detectable stuck-at faults but stuck-open and stuck-on faults as well. Very few stuck-open faults require two-pattern tests, and very few stuck-on faults need current monitoring. Thus, zipper CMOS circuits in particular and dynamic CMOS circuits in general enjoy a huge testability advantage over static CMOS circuits. Faults in the driver circuit are also considered.<
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