Monitoring on-chip clock control during integrated circuit testing

Abstract

The On-Chip Clock (OCC) circuit is for testing an integrated circuit having logic blocks connected in scan chains. An OCC controller is configured to receive a plurality of clock signals and output a plurality of shift/capture clock signals for use by the scan chains of logic blocks, the plurality of shift/capture clock signals including at least two consecutive at-speed capture clock pulses. An OCC monitor is configured to provide a verification of OCC operation based upon the at least two consecutive at-speed capture clock pulses. The OCC monitor may include a plurality of registers configured to provide delayed pulses based upon the at least two consecutive at-speed capture clock pulses, a counter configured to count differences between the delayed pulses, and an output register coupled to the counter and configured to provide a static data verification (e.g. output on an integrated circuit pad) for the test engineer.