Datasheet

1361
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
44.6.8 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 canceled.
The protected registers are:
DACC Mode Register
DACC Channel Enable Register
DACC Channel Disable Register
DACC Analog Current Register