Design-for-Current-Testability (DFCT) for Dynamic CMOS Logic

The applicability of quiescent current monitoring (IDDQ testing) to dynamic logic is discussed here. IDDQ is very useful in detecting some defects that can escape functional and delay tests, however, we show that some defects in domino logic cannot be detected by either voltage or current measurements. A design-for-current-testability (DFCT) modification for dynamic logic is presented and shown to enable detection of these defects. The DFCT circuitry is designed with a negligible performance impact during normal operation. This is particularly important since the main reason for using dynamic logic is because of its speed.