An extended host controller test mode support is provided. In the example of USB host controllers, an enhanced host controller is provided to control the high-speed traffic. Further at least one companion host controller controls the full-speed and/or low-speed traffic. The enhanced host controller comprises a test circuit for controlling a USB transceiver macrocell to perform full-speed and/or low-speed test functions. The test functions may include a test-J function, a test-K function, a single-ended-zero test function, and the sending of test patterns.