Per LPC435x specification, Cortex-M0 is not accessible through the SWD
debug interface. It’s accessible only through the JTAG debug interface.
It’s recommended to use the JTAG debug interface when debugging LPC435x, which allows debugging both Cortex-M4 and Cortex-M0 cores.
If only the SWD debug interface is available on the target debug
connector, only Cortex-M4 can be debugged.
1. Go to Hardware | CPU Options | Cores | CortexM0.
2. Uncheck the Automatically observe this core option.
Without this adjustment, winIDEA might become unresponsive when attempting to connect to the Cortex-M0 core.