Datasheet

817
SAM4S Series [DATASHEET]
11100F–ATARM–29-Jan-14
36.8.22 USART Write Protection Mode Register
Name: US_WPMR
Address: 0x400240E4 (0), 0x400280E4 (1)
Access: Read/Write
Reset: See Table 36-16
• WPEN: Write Protection Enable
0: Disables the write protection if WPKEY corresponds to 0x555341 (“USA” in ASCII).
1: Enables the write protection if WPKEY corresponds to 0x555341 (“USA” in ASCII).
See Section 36.7.10 ”Register Write Protection” for the list of registers that can be wirte-protected.
• WPKEY: Write Protection Key
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
Value Name Description
0x555341 PASSWD
Writing any other value in this field aborts the write operation of the WPEN bit. Always reads
as 0.