Connecting to a JTAG target
When connecting to a Cortex-M part, by default, the debugger will attempt to connect using SWD. If you need to connect via JTAG, then you must make a debugger configuration change as follows:
- Select your project in Project Explorer
Right-click and select Launch Configurations->Open Current Launch Configuration
- In the dialog, ensure your projects Debug configuration is selected
- Select the Debugger tab
in the table under Script Values, scroll the list and select the option Debug interface
- Select "JTAG" from the drop-down list
- Press Apply and then Debug
The debugger will now connect using JTAG instead of SWD.
The first time that you connect to a target over JTAG, a pop up dialog will appear for you to select which device on the JTAG scan chain to connect to. For more details see the FAQ "Multiple devices on a JTAG scan chain.
Some Cortex-M based MCU's only support debugging via SWD, and not via JTAG. Please check the documentation for the MCU that you are using for more information.