at32uc3b0512-z2ues ATMEL Corporation, at32uc3b0512-z2ues Datasheet - Page 379

• Manufacturer Part Number: at32uc3b0512-z2ues
• Description: 32-bit Avr Microcontroller
• Manufacturer: ATMEL Corporation

22.7.1.8
22.7.1.9
32059J–12/2010
Plug-In detection
ID detection
The SUSP bit is set and the Wake-Up Interrupt (WAKEUP) bit in UDINT 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 written to
one. It returns to the Active state when USBE is written to one and DETACH is written to zero.
The USB connection is detected from the USB_VBUS pad.
architecture of the plug-in detector.
Figure 22-11. Plug-In Detection Input Block Diagram
The control logic of the USB_VBUS pad outputs two signals:
• The Session_valid signal is high when the voltage on the USB_VBUS pad is higher than or
• The Va_Vbus_valid signal is high when the voltage on the USB_VBUS pad is higher than or
In device mode, the USBSTA.VBUS bit follows the Session_valid comparator output:
• It is set when the voltage on the USB_VBUS pad is higher than or equal to 1.4V.
• It is cleared when the voltage on the VBUS pad is lower than 1.4V.
In host mode, the USBSTA.VBUS bit follows an hysteresis based on Session_valid and
Va_Vbus_valid:
• It is set when the voltage on the USB_VBUS pad is higher than or equal to 4.4V.
• It is cleared when the voltage on the USB_VBUS pad is lower than 1.4V.
The VBus Transition interrupt (VBUSTI) bit in USBSTA is set on each transition of the USB-
STA.VBUS bit.
The USBSTA.VBUS bit is effective whether the USBB is enabled or not.
Figure 22-12 on page 380
equal to 1.4V.
equal to 4.4V.
USB_VBUS
Pad Logic
shows how the ID transitions are detected.
GND
VDD
Session_valid
Va_Vbus_valid
VBus_pulsing
VBus_discharge
Logic
USBSTA
Figure 22-11 on page 379
VBUS
AT32UC3B
VBUSTI
USBSTA
shows the
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