Debugging the Connection Test

Running a Connection Test will drive signals on the nets connected to JTAG devices, which can reveal mistakes or omissions in the project setup. For example, the JTAG chain may stop working when a particular pin is toggled, or the current consumption may increase suddenly if a net ends up in contention.

The Debug Connection Test screen is provided to track down these types of problems and can be accessed via XJDeveloper or XJInvestigator.

The Debug Connection Test screen works by changing the state of one net at a time, working through a sequence of states, with the aim that at some point in this sequence, you will be able to recreate the broken JTAG chain or high current consumption, and so identify the net that caused the problem.