Datasheet

847
42023E–SAM–07/2013
ATSAM4L8/L4/L2
Figure 31-3. SleepWalking™ on Peripheral Events
31.5.3 Clocks
The PEVC has two clocks connected: one Peripheral Bus clock (CLK_PEVC) and the system
RC oscillator clock (CLK_RCSYS). These clocks are generated by the Power Manager.
CLK_PEVC is required for event propagation and Peripheral Bus operations.
CLK_RCSYS is used for glitch filtering in Event Shapers. It is required for event propagation in
case glitch filtering is turned on for a given generator.
5
incoming Event j propagates to Channel i:
• CLK_USER i request to PM
• TRIG i forwarded to User i
6 CLK_USER i wakes up
7 User i handles the incoming Peripheral Event and signals it to PEVC
8
depending on the Peripheral’s operation, a CPU wake request occurs in case of
Interrupt processing
9
alternatively, the Peripheral may simply go back to sleep, in which case PM will
silently shut off CLK_USER i and CLK_PEVC
Table 31-2. SleepWalking™ on Peripheral Events
Phase Operation
Channel
i
PEVC
EVS
j
Generator
j
User
i
TRIG i
EVT j RDY i
CLK_USER i
Power Manager
CLK_USER i
Wake CPU
IRQ USER i
1
2
5
7
8
6
5
4
Wake Clock Sources
CLK_PEVC
3