Peripheral access control can be enabled or disabled by writing to the WRCTRL register.
The data written to the WRCTRL register is composed of two fields; WRCTRL.PERID and WRCTRL.KEY. The WRCTRL.PERID is an unique identifier corresponding to a peripheral. The WRCTRL.KEY is a key value that defines the operation to be done on the control access bit. These operations can be “clear protection”, “set protection” and “set and lock protection bit”.
The “clear protection” operation will remove the write access protection for the peripheral selected by WRCTRL.PERID. Write accesses are allowed for the registers in this peripheral.
The “set protection” operation will set the write access protection for the peripheral selected by WRCTRL.PERID. Write accesses are not allowed for the registers with write protection property in this peripheral.
The “set and lock protection” operation will permanently set the write access protection for the peripheral selected by WRCTRL.PERID. The write access protection will only be cleared by a hardware reset.
The peripheral access control status can be read from the corresponding STATUSn register.