Frequency andPowerCorrelation betweenAt-Speed ScanandFunctional Tests

At-Speed scan isa keytechnique inmodernIC testing. Oneofitsdrawbacks, withrespectto functional tests, isitsexcessive power consumption leading tovoltage dropandfrequency degradation. This paper discusses thefrequency andpower correlation between At-Speed Scanandfunctional tests. Theinfluence ofvoltage drop onfrequency is demonstrated by silicon measurementsand supportingsimulation results. Thelocalized natureofthevoltage drop as well as impedance componentanalysis are presented. Additionally, theneedforpower aware scan patterns isalso discussed. Suggestions forachieving a higher correlation between At-Speed scan andfunctional patterns, withrespect topower consumption, are offered.