At-speed logic BIST using a frozen clock testing strategy

We present a new approach to built-in self-test (BIST) for logic circuits that achieves comparable fault coverages to scan BIST with less hardware overhead and no impact on performance. We combine clock partitioning to create independent clocks with a selective freezing of clock signals to form various pipeline configurations during testing. Since no scan operations are performed, tests can be applied at the operational speed of the circuit. Experimental results are presented for several benchmark circuits to demonstrate the effectiveness of the approach