IEEE1149IEEE Std 1149.1-2001 (Revision of IEEE Std 1149.1-1990) IEEE Standard Test Access Port and Boundary-Scan Architecture Sponsor Test Technology Standards Committee of the IEEE Computer Society Approved 14 June 2001 IEEE-SA Standards Board Abstract: Circuitry that may be built into an integrated circuit to assist in the test, maintenance, and support of assembled printed circuit boards is defined. The circuitry includes a standard interface through which instructions and test data are communicated. A set of test features is defined, including a boundary-scan register, such that the component is able to respond to a minimum set of instructions designed to assist with testing of assembled printed circuit boards. Also, a language is defined that allows rigorous description of the component-……