Methods and apparatus for testing a semiconductor device. A testing interface is configured to interface with an external test apparatus and a device under test (DUT). In one embodiment, the testing interface receives test data and a test clock signal from the external test apparatus. The test data is clocked out of the testing interface and to the DUT according to the test clock signal. Further, the test clock signal is delayed by a period of time and then a delayed clock signal is issued to the device. The data previously written to the DUT is read out of the DUT and compared with the test data received from the external test apparatus. The period of time by which the test clock signal is delayed can be varied to achieve a desired timing.