Built in self test (bist) for clock generation circuitry

Abstract

Testing clock division circuitry includes generating pseudo random test pattern bits for scan chain logic in programmable clock division logic circuitry and divided clock counter circuitry. A shift clock is used to shift the test pattern bits into the scan chain logic. A capture clock signal is used in the programmable clock division logic during a non-test mode of operation. The shift clock is used to provide output shift bits from the scan chain logic to a multi-input shift register (MISR). Once all the output shift bits for the test pattern bits are provided to the MISR, a final test signature from the MISR is compared to an expected test signature to determine whether the programmable clock division logic circuitry and divided clock counter circuitry are free of faults.