20.11.2.2 Operation From a Debug Adapter

Debug adapters should access the DSU registers in the external address range 0x100 – 0x1FFF. If the device is protected by the NVMCTRL 26.5.6 Security Bit and Chip Erase Hard Lock Bit, accessing the first 0x100 bytes causes the system to return an error. Refer to 20.9 Intellectual Property Protection.