![](http://datasheet.mmic.net.cn/100000/IF180C52TXXX-20R_datasheet_3493957/IF180C52TXXX-20R_585.png)
585
32099I–01/2012
AT32UC3L016/32/64
25.4.2
Peripheral Event Connections
Each generated peripheral event is connected to one or more users. If a peripheral event is con-
nected to multiple users, the peripheral event can trigger actions in multiple modules.
A peripheral event user can likewise be connected to one or more peripheral event generators. If
a peripheral event user is connected to multiple generators, the peripheral events are OR’ed
together to a single peripheral event. This means that peripheral events from either one of the
generators will result in a peripheral event to the user.
To configure a peripheral event, the peripheral event must be enabled at both the generator and
user side. Even if a generator is connected to multiple users, only the users with the peripheral
event enabled will trigger on the peripheral event.
25.4.3
Low Power Operation
As the peripheral events do not require CPU intervention, they are available in Idle mode. They
are also available in deeper sleep modes if both the generator and user remain clocked in that
mode.
Certain events are known as asynchronous peripheral events, as identified in
Table 25-1 to
Table 25-4. These can be issued even when the system clock is stopped, and revive unclocked
user peripherals. The clock will be restarted for this module only, without waking the system from
sleep mode. The clock remains active only as long as required by the triggered function, before
being switched off again, and the system remains in the original sleep mode. The CPU and sys-
Table 25-3.
Peripheral Event Mapping from AST
Generator
Generated Event
User
Effect
Asynchronous
AST
Overflow event
ACIFB
Comparison is triggered if the ACIFB.CONFn
register is written to 11 (Event Triggered Single
Measurement Mode) and the EVENTEN bit in
the ACIFB.CTRL register is written to 1.
Yes
Periodic event
Alarm event
Overflow event
ADCIFB
Conversion is triggered if the TRGMOD bit in
the ADCIFB.TRGR register is written to 111
(Peripheral Event Trigger).
Periodic event
Alarm event
Overflow event
CAT
Trigger one iteration of autonomous touch
detection.
Periodic event
Alarm event
Table 25-4.
Peripheral Event Mapping from PWMA
Generator
Generated Event
User
Effect
Asynchronous
PWMA channel 0
Timebase counter
reaches the duty cycle
value.
ACIFB
Comparison is triggered if the ACIFB.CONFn
register is written to 11 (Event Triggered Single
Measurement Mode) and the EVENTEN bit in
the ACIFB.CTRL register is written to 1.
No
ADCIFB
Conversion is triggered if the TRGMOD bit in
the ADCIFB.TRGR register is written to 111
(Peripheral Event Trigger).