The chain gang
Boundary scan test is a must for designers using fpgas and cplds. By Dominic Plunkett.
Reconfigurable components such as fpgas give engineers greater flexibility to update designs quickly and to deliver new products to an aggressive roadmap. But there can be untested hardware faults in circuitry that is not used until the upgrade is applied. Engineers need fast and effective techniques to test this dormant hardware.
With the prices of fpgas, cplds and mcus falling, it is becoming common for engineers to implement new features by reprogramming existing hardware or by updating software, bypassing the redesign of fundamental hardware. Upgrading by reprogramming also allows engineers to respond quickly to emerging standards, as is common in mobile communications. It can also ease customisation of designs to meet individual customer requirements.
