Doing more with less - An IEEE 1149.7 embedded tutorial : Standard for reduced-pin and enhanced-functionality test access port and boundary-scan architecture

Abstract

IEEE Std 1149.7 offers a means to reduce chip pins dedicated to test (and debug) access while enhancing the functionality of the Test Access Port (TAP) as a complementary superset of the original IEEE Std 1149.1 (JTAG). Extended features such as hot-plug immunity, power management, optimization of scan throughput, access to instrumentation, and access to custom technologies provide welcome improvements for debug. Further, the boundary-scan architecture is bolstered to ensure full support for test. This important advancement in test and debug interfaces is well suited for access to multiple cores on SOC or multiple die in SIP or POP.