XJTAG Troubleshooting

This troubleshooting guide is provided to help the user locate a problem and hence help solve various issues associated with the XJTAG system. The troubleshooting guide is divided into these sections:

Project setup

Sometimes options need to be set to workaround issues with the files provided by other tools for project setup.

JTAG chain bring-up

This troubleshooter is used to help with problems encountered when first trying to run the JTAG chain, for example if no data is returned, or the hardware is detected but the wrong number of devices is found.

Connection test

This covers problems when running the connection test - e.g. current consumption suddenly increasing at a particular stage of the connection test (meaning that there is a contention on the circuit). Also includes notes on interpreting the errors reported.

XJEase

This is used to cover the more general problems often encountered when using XJEase to create tests for various types of system. E.g. problems writing/reading from devices, possible things which could be at fault etc.

Signal integrity / reliability

If results are inconsistent, if the chain only sometimes works, or if broken chains occur randomly at different places during testing, it may be that there are signal integrity issues around the JTAG signals on your PCB.

Technical Support

Obtaining technical support.