IEEE 1149.6 is a standard developed by the Institute of Electrical and Electronics Engineers that focuses on testing integrated circuits. It enhances the existing IEEE 1149.1 standard, also known as the JTAG standard, by providing additional capabilities for testing high-speed digital circuits. This is particularly useful for ensuring the reliability and performance of modern electronic devices. The standard introduces techniques for testing signals that are not easily accessible through traditional methods. By allowing for the testing of AC and DC signals, IEEE 1149.6 helps engineers identify faults in complex systems, improving overall product quality and reducing time-to-market for new technologies.