JTAG System Test in a MicroTCA World

The telecommunications industry has developed new system architectures through the PCI Industrial Computer Manufacturers Group (PICMG) organization. These are the Advanced Telecom Computing Architecture (ATCA) platforms that consist of the ATCA, ATCA300, Advanced Mezzanine Card (AMC), and MicroTCA specifications. Unfortunately, only the AMC and MicroTCA specification directly addresses testability using an IEEE Std 1149.1 (JTAG) compatible interface. This paper will address the system test facility specified in the MicroTCA specification for testing the incorporated AMC modules as well as the MicroTCA Carrier Hub (MCH) controllers. Access to the individual AMC JTAG chains is provided using a JTAG Switch Module that provides a programmable star architecture in the system.