An improvement in a scan testing method for testing a circuit having
memory elements arranged into one or more scan chains, the scan testing
method having a shift phase for serially loading test patterns into the
scan chains and serially unloading test response patterns from the scan
chains and a capture phase for capturing the response of the circuit to
the test pattern, includes, during the capture phase, connecting the
serial output of each scan chain to its serial input and applying a
predetermined number of capture clock cycles with the memory elements
configured in a non-capture mode for all but the last capture clock cycle
and configured in capture mode for the last capture clock cycle.