Datasheet

972
SAM4S Series [DATASHEET]
11100F–ATARM–29-Jan-14
39.7.30 PWM Write Protection Control Register
Name: PWM_WPCR
Address: 0x400200E4
Access: Write-only
• WPCMD: Write Protect Command
This command is performed only if the WPKEY value is correct (0x50574D, “PWM” in ASCCII).
• WPRGx: Write Protect Register Group x
0: The WPCMD command has no effect on the register group x.
1: The WPCMD command is applied to the register group x.
• WPKEY: Write Protect Key
List of register groups:
• Register group 0:
– “PWM Clock Register” on page 943
• Register group 1:
– “PWM Disable Register” on page 945
• Register group 2:
– “PWM Sync Channels Mode Register” on page 951
– “PWM Channel Mode Register” on page 979
– “PWM Stepper Motor Mode Register” on page 971
• Register group 3:
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
WPRG5 WPRG4 WPRG3 WPRG2 WPRG1 WPRG0 WPCMD
Value Name Description
0 DISABLE_SW_PROT Disable the Software Write Protect of the register groups of which the bit WPRGx is at ‘1’.
1 ENABLE_SW_PROT Enable the Software Write Protect of the register groups of which the bit WPRGx is at ‘1’.
2 ENABLE_HW_PROT
Enable the Hardware Write Protect of the register groups of which the bit WPRGx is at ‘1’. Only a
hardware reset of the PWM controller can disable the hardware write protect. Moreover, to meet
security requirements, the PIO lines associated with PWM can not be configured through the PIO
interface.
Value Name Description
0x50574D PASSWD
Writing any other value in this field aborts the write operation of the WPCMD field.
Always reads as 0