The JTAG mode is also a serial configuration mode, popular for prototyping and highly used for board test. The four-pin JTAG boundary scan interface is common on board testers and debugging hardware. The AMD programming cables for UltraScale architecture-based FPGAs use the JTAG interface for prototype download and debugging. Regardless of the configuration mode ultimately used in the application, it is best to also include a JTAG configuration path to ease design development. See the following figure.
Figure 1. JTAG Configuration Mode
