IEEE 1149.1 (JTAG)

IEEE 1149.1, commonly known as JTAG (Joint Test Action Group), is a standard that provides a systematic way to test and program electronic devices, especially integrated circuits on circuit boards. It uses a dedicated set of pins and a structured protocol to access internal components, allowing technicians to diagnose hardware issues, perform boundary scan tests, and update firmware without physically removing chips. Essentially, JTAG serves as a digital interface for inspecting, troubleshooting, and configuring hardware through a standardized, efficient process, improving reliability and reducing testing complexity in electronic systems.