Periodic Events

The AST can generate events at periodic intervals, allowing for direct peripheral actions without CPU intervention. The periodic events can be generated on an AST prescaler match, and will be generated on the rising edge transition of the specified bit. The resulting periodic frequency can be calculated by the following formula:

fPERIODIC=fASY2n+1
Where
fASY
refers to the asynchronous clock set up in the AST module configuration.
Note: The connection of events between modules requires the use of the SAM4L Peripheral Event Controller (PEVC) to route an output event of one module to the the input event of another. For more information on event routing, refer to the event driver documentation.