Datasheet

508
AT32UC3A
30.7.1.7 Pad Suspend
Figure 30-9 shows the pad behavior.
Figure 30-9. Pad Behavior
• In the Idle state, the pad is put in low power consumption mode.
• In the Active state, the pad is working.
Figure 30-10 illustrates the pad events leading to a PAD state change.
Figure 30-10. Pad Events
The Suspend interrupt flag (SUSP) is set and the Wake-Up interrupt flag (WAKEUP) is cleared
when a USB “Suspend” state has been detected on the USB bus. This event automatically puts
the USB pad in the Idle state. The detection of a non-idle event sets WAKEUP, clears SUSP and
wakes up the USB pad.
Moreover, the pad goes to the Idle state if the macro is disabled or if the DETACH bit is set. It
returns to the Active state when USBE = 1 and DETACH = 0.
Idle
Active
USBE = 1
& DETACH = 0
& Suspend
USBE = 0
| DETACH = 1
| Suspend
SUSP
Suspend detected Cleared by hardware on wake-up
Wake-up detected Cleared by software to acknowledge the interrupt
WAKEUP
PAD State
Active
Idle
Active
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AVR32-01/12