IEEE Standard Test Access Port and Boundary-Scan Architecture

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.