When troubleshooting the initial debug connection to the target CPU, it is recommended to use the CPU Reset debug command instead of Download debug command.
Check if BlueBox is properly connected to the target debug connector through use of proper BlueBox debug adapter.
Double check that the pinout of the target debug connector matches with the one from the debug adapter.
If the debugger cannot connect to the CPU or just loses control over the CPU after some time, check if there is any active watchdog (CPU internal or external on the embedded target). Try to connect to the CPU and run the application by disabling all watchdogs first:
If you cannot establish debug connection to a safety CPU such as P1x family, it might be that part of the application is executed right after reset and it triggers a safety exception, which locks the debug interface.
See the Code Execution on Session Startup chapter for more details on how to resolve the issue.
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