Datasheet

SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
854
35.8.18 USART Write Protect Mode Register
Name: US_WPMR
Address: 0x400980E4 (0), 0x4009C0E4 (1), 0x400A00E4 (2), 0x400A40E4 (3)
Access: Read-write
Reset: See Table 35-17
• WPEN: Write Protect Enable
0 = Disables the Write Protect if WPKEY corresponds to 0x555341 (“USA” in ASCII).
1 = Enables the Write Protect if WPKEY corresponds to 0x555341 (“USA” in ASCII).
Protects the registers:
• “USART Mode Register” on page 827
• “USART Baud Rate Generator Register” on page 843
• “USART Receiver Time-out Register” on page 844
• “USART Transmitter Timeguard Register” on page 845
• “USART FI DI RATIO Register” on page 846
• “USART IrDA FILTER Register” on page 848
• “USART Manchester Configuration Register” on page 849
• WPKEY: Write Protect KEY
Should be written at value 0x555341 (“USA” in ASCII). Writing any other value in this field aborts the write operation of the
WPEN bit. Always reads as 0.
31 30 29 28 27 26 25 24
WPKEY
23 22 21 20 19 18 17 16
WPKEY
15 14 13 12 11 10 9 8
WPKEY
76543210
———————WPEN