Low-volume, high-value circuits and systems as found in military and aerospace systems are ideally suited for testing using boundary-scan technology. For example, signal processing systems such as those found in airborne radars will feature boards with thousands of interconnects, many buried within the substrate of a PCB. This alone makes it impossible to fully test them using older, ICT (In Circuit Test) technology. Boundary-scan however simplifies testing of high-density interconnects since test access is embedded with the digital devices used. What's more boundary-scan will also reduce the test equipment design burden by reducing the requirements within functional test. Indeed many military customers will demand that their in-service equipment features a degree of built-in test, and an ability to up-issue embedded code, that is controlled via JTAG/boundary-scan.