Datasheet

258
7593L–AVR–09/12
AT90USB64/128
• 3 – SPEED: Speed Status Flag
This should be read only when the USB controller operates in host mode, in device mode the
value read from this bit is undeterminated.
Set by hardware when the controller is in FULL-SPEED mode. Cleared by hardware when the
controller is in LOW-SPEED mode.
• 2 – Reserved
The value read from this bit is always 0. Do not set this bit.
• 1 – ID: IUD pin flag
The value read from this bit indicates the state of the UID pin.
• 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 Section 22.10, page 255
for more details.
7-2 - Reserved
The value read from these bits is always 0. Do not set these bits.
1 – IDTI: D Transition Interrupt flag
Set by hardware when a transition (high to low, low to high) has been detected on the UID pin.
Shall be cleared by software.
• 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.
Shall be cleared by software.
• 7-6 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 5 – HNPREQ: HNP Request bit
Set to initiate the HNP when the controller is in the Device mode (B). Set to accept the HNP
when the controller is in the Host mode (A).
Clear otherwise.
Bit 76543210
------IDTIVBUSTIUSBINT
Read/writeRRRRRRR/WR/W
Initial value00000000
Bit 7 6 5 4 3 2 1 0
- - HNPREQ SRPREQ SRPSEL VBUSHWC VBUSREQ VBUSRQC OTGCON
Read/write R R R/W R/W R/W R/W R/W R/W
Initial value 0 0 0 0 0 0 0 0