Atmel Xplained Pro Evaluation Kit ATSAM4E-XPRO ATSAM4E-XPRO Data Sheet

SAM4E [DATASHEET]

Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14

1044

It is possible to change the update period of synchronous channels while they are enabled. See “Method 2:
Manual write of duty-cycle values and automatic trigger of the update” on page 1036 and “Method 3: Automatic
write of duty-cycle values and automatic trigger of the update” on page 1037.

To prevent an unexpected update of the synchronous channels registers, the user must use the 

 (PWM_SCUPUPD) to change the update period of synchronous

channels while they are still enabled. This register holds the new value until the end of the update period of
synchronous channels (when UPRCNT is equal to UPR in PWM_SCUP) and the end of the current PWM period,
then updates the value for the next period.

Note:

If the update register PWM_SCUPUPD is written several times between two updates, only the last written value is 
taken into account.

Note:

Changing the update period does make sense only if there is one or more synchronous channels and if the update 
method 1 or 2 is selected (UPDM = 1 or 2 in 

).

PWM_CPRDUPDx Value

PWM_CPRDx

PWM_CDTYx

- If Asynchronous Channel
   -> End of PWM period
- If Synchronous Channel
   -> End of PWM period and UPDULOCK = 1

User's Writing

PWM_DTUPDx Value

User's Writing

PWM_DTx

- If Asynchronous Channel
   -> End of PWM period
- If Synchronous Channel
   - If UPDM = 0
      -> End of PWM period and UPDULOCK = 1
   - If UPDM = 1 or 2
      -> End of PWM period and end of Update Period

PWM_CDTYUPDx Value

User's Writing