AT32UC3A3256S_2 Datasheet, PDF (601/1014 Pages) ATMEL Corporation – 32-bit AVR®Microcontroller

AT32UC3A3/A4
25.6.16 Write Protection Registers
To prevent any single software error that may corrupt USART behavior, certain address spaces can be write-protected by
setting the WPEN bit in the USART Write Protect Mode Register (WPMR).
If a write access to the protected registers is detected, then the WPVS flag in the USART Write Protect Status Register
(WPSR) is set and the field WPVSRC indicates in which register the write access has been attempted.
The WPVS flag is reset by writing the USART Write Protect Mode Register (WPMR) with the appropriate access key,
WPKEY.
The protected registers are:
• ”Mode Register” on page 605
• ”Baud Rate Generator Register” on page 615
• ”Receiver Time-out Register” on page 616
• ”Transmitter Timeguard Register” on page 617
• ”FI DI RATIO Register” on page 618
• ”IrDA FILTER Register” on page 620
• ”Manchester Configuration Register” on page 621
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