The User Information Configuration Registers (UICR)s have not been previously configured to enable access port protection.
If the device is in secure protection, you cannot read Factory Information Configuration Registers (FICR)s or disable the System Protection Unit (SPU). To disable Secure Access Port Protection (SECUREAPPROTECT) , see Erasing all through CTRL-AP.
In some cases, you may assume that the entire flash has already been erased. If the flash is already erased and the device has never been programmed before, go to Programming the application core.