Datasheet

1022

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

42.6.8 Write Protection Registers

In order to provide security to the DACC, a write protection system has been implemented.

The write protection mode prevents the writing of certain registers. When this mode is enabled and one of the protected

registers is written, an error is generated in the DACC Write Protect Status Register and the register write request is

canceled. When a write protection error occurs, the WPROTERR flag is set and the address of the corresponding

canceled register write is available in the WPROTADRR field of the DACC Write Protect Status Register.

Due to the nature of the write protection feature, enabling and disabling the write protection mode requires the use of a

security code. Thus when enabling or disabling the write protection mode the WPKEY field of the DACC Write Protect

Mode Register must be filled with the “DAC” ASCII code (corresponding to 0x444143) otherwise the register write is