at32uc3b0512-z2ues ATMEL Corporation, at32uc3b0512-z2ues Datasheet - Page 380

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

32059J–12/2010
Figure 22-12. ID Detection Input Block Diagram
The USB mode (device or host) can be either detected from the USB_ID pin or software
selected by writing to the UIMOD bit, according to the UIDE bit. This allows the USB_ID pin to be
used as a general purpose I/O pin even when the USB interface is enabled.
By default, the USB_ID pin is selected (UIDE is written to one) and the USBB is in device mode
(UBSTA.ID is one), what corresponds to the case where no Mini-A plug is connected, i.e. no
plug or a Mini-B plug is connected and the USB_ID pin is kept high by the internal pull-up resis-
tor from the I/O Controller (which must be enabled if USB_ID is used).
The ID Transition Interrupt (IDTI) bit in USBSTA is set on each transition of the ID bit, i.e. when a
Mini-A plug (host mode) is connected or disconnected. This does not occur when a Mini-B plug
(device mode) is connected or disconnected.
The USBSTA.ID bit is effective whether the USBB is enabled or not.
USB_ID
I/O Controller
VDD
UIMOD
USBCON
USBCON
1
0
UIDE
USBSTA
ID
AT32UC3B
USBSTA
IDTI
380