Monitoring and Collection of Signal Information

XJAnalyser allows you to monitor and record information about signal levels on the board, which allows it to perform as a type of highly flexible logic analyser. The Pin Watch functionality can be set to monitor any pins which change, so you can apply an input to the circuit (either using XJAnalyser or an external source) and see which pins react.

The TCK pin clock speed and the length of the JTAG chain place some limitations on the data rate which can be sampled.

Because of the above speed limitations, it can be important to capture information using as short a scan chain as possible. This is achieved by placing only the devices of immediate interest into EXTEST mode, and all remaining devices into a JTAG inactive state, preferably CLAMP or alternatively BYPASS mode.