Chain Setup

The Chain Setup panel lists the JTAG chains currently defined in the project. The easiest way to identify the JTAG chains in your project is to click Suggest Chains... and use the Suggest JTAG Chains dialog. This can be used to identify any JTAG chains in your project given only the relevant BSDL files, even without any hardware connected. If this is unsuccessful, you can manually configure the JTAG chain(s), working through from TDI to TDO.

Up to 4 chains can be used with an XJLink2-based JTAG controller.

• Suggest Chains... - Displays the Suggest JTAG Chains dialog, where JTAG chains can be automatically identified and configured.

• Add... - Displays a dialog allowing you to configure a new JTAG Chain. This dialog allows you to name the chain as well as set its TDI and TDO pins. Typically these will be pins on a connector and are the start and end points of the JTAG chain. The dialog also has a Suggest... button which launches the Suggest JTAG Chains dialog.

  
• Edit... - Allows the name, TDI and TDO of an existing chain to be edited.
• Remove - Removes a JTAG chain.
• Move Up - Moves the selected chain to the previous TAP Index.
• Move Down - Moves the selected chain to the next TAP Index.
• Check Termination - This checkbox enables or disables checks and warnings about potential poor termination of TAP signals on the JTAG chain. Termination is important in order to achieve good TCK speeds and to minimise bit error rates in the JTAG communication with the circuit. More details are given in the XJTAG DFT guidelines, on the XJTAG website.