Datasheet

268
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
• Bits 7:2 - Reserved
The value read from these bits is always 0. Do not set these bits.
• Bit 1 - ID: ID status
This bit is always read as “1”, it has been conserved for compatibility with AT90USB64/128 (in which it indicates
the value of the OTG ID pin).
• Bit 0 – VBUS: VBus Flag
The value read from this bit indicates the state of the VBUS pin. This bit can be used in device mode to monitor
the USB bus connection state of the application. See “Plug-in Detection” on page 265 for more details.
• Bits 7:1 - Reserved
The value read from these bits is always 0. Do not set these bits.
• Bit 0 – VBUSTI: IVBUS Transition Interrupt Flag
Set by hardware when a transition (high to low, low to high) has been detected on the VBUS pad. This shall be
cleared by software (see “USB Software Operating Modes” on page 266).
Bit 7 6 5 4 3 2 1 0
- - - - - - ID VBUS USBSTA
Read/WriteRRRRRRRR
Initial Val-
ue
00000 0 1 0
Bit 76543210
- - - - - - - VBUSTI USBINT
Read/Write R R R R R R R/W R/W
Initial Val-
ue
00000000