A scan clock modifier, a method of providing a variable scan clock, an IC including a scan clock modifier and a library including a cell of a scan clock modifier. In one embodiment, the scan clock modifier includes: (1) logic circuitry configured to provide at least one selected clock signal based on a test scan clock signal and a first clock control signal, both of the test scan clock signal and the first clock control signal received from test equipment and (2) comparison logic configured to provide a scan clock signal based on the at least one selected clock signal and at least one other clock control signal received from the test equipment, wherein the first and the at least one other clock control signals are different clock control signals.