Abstract: A method is provided for overcoming the slow speed of accessing machine state information from a device under test using boundary scan technology. The method minimizes the total number of words sent over the lengthy communications path by filtering out intermediary data. The method enables transfers of results to take place while other boundary scan circuitry commands are executing. Firmware is provided that transforms a boundary scan circuitry controller into a debug controller. Building the debug functions into the system makes it possible to have debug capability from module level integration all the way to system level integration.