Abstract: Test packets may be received at a design under test (DUT) from an automated test equipment (ATE) over a serializer/deserializer (SERDES) connection between the ATE and the DUT. The test packets may include test pattern data to test the DUT. The test pattern data may be applied to the DUT using a set of scan chains and test response data corresponding to the test pattern data may be obtained. The test response data may be received by a circuit in the DUT at irregular time intervals. Response packets may be sent to the ATE by the circuit in the DUT at regular time intervals, where the response packets may include a portion of the test response data (which may be encoded using an encoding technique), and where the response packets may be sent to ATE over the SERDES connection.