A method and apparatus for implementing mode based skew is disclosed. In one embodiment, an IC includes a number of different functional units each coupled to receive a respective one of a number of different clock signals. One or more of the functional circuit blocks includes at least two clock-gating circuits that are coupled to receive the clock signal provided to that functional circuit block. During a scan test, a first clock-gating circuit within a functional circuit block is configured to provide a first delay to the clock signal. A second clock-gating circuit within the functional circuit block may provide a second delay to the clock signal, the second delay being different from the first.