At-speed bitmapping in a memory built-in self-test by locking an N-TH failure

摘要

In a sophisticated semiconductor device including a large memory portion, a built-in self-test circuitry comprises a failure capturing logic that allows the capturing of a bitmap at a given instant in time without being limited to specific operating conditions in view of interfacing with external test equipment. Thus, although pipeline processing may be required due to the high speed operation during the self-test, reliable capturing of the bitmap may be achieved while maintaining high fault coverage of the test algorithm under consideration.