Datasheet

877
32117D–AVR-01/12
AT32UC3C
Figure 32-5. Pad events
The Suspend Interrupt bit in the Device Global Interrupt register (UDINT.SUSP) is set and the
Wakeup Interrupt (UDINT.WAKEUP) bit 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 the USB pad.
The pad goes to the Idle state if the module is disabled or if UDCON.DETACH is written to one.
It returns to the Active state when USBCON.USBE is written to one and DETACH is written to
zero.
32.6.1.7 Customizing of Embedded Host timers
It is possible to refine some timers thanks to the Timer Page (TIMPAGE) and Timer Value (TIM-
VALUE) fields in USBCON, as shown in Table 32-3.
TIMPAGE is used to select the timer to be accessed while TIMVALUE indicates the time-out
value of the selected timer.
TIMPAGE and TIMVALUE can be read and written. Before writing them, the user shall unlock
write accesses by writing a one to the Timer Access Unlock (UNLOCK) bit in USBCON.
32.6.1.8 Plug-in detection
The USB connection is detected by the USB_VBUS pad. Figure 32-6 shows the architecture of
the plug-in detector.
SUSP
Suspend detected Cleared on Wakeup
Wakeup detected Cleared by software to acknowledge the interrupt
WAKEUP
PAD state
Active
Idle
Active
Table 32-3. Customizing of Host Timers
TIMPAGE
0b00
AWaitVrise Time-Out
0b01
VbBusPulsing Time-Out
0b10
PdTmOutCnt Time-Out
0b11
SRPDetTmOut Time-Out
TIMVALUE
00 20 ms 15 ms 93 ms 10 µs
01 50 ms 23 ms 105 ms 100 µs
10 70 ms 31 ms 118 ms 1 ms
11 100 ms 40 ms 131 ms 11 ms