AT90USB1286-16MU ATMEL [ATMEL Corporation], AT90USB1286-16MU Datasheet - Page 267

• Manufacturer Part Number: AT90USB1286-16MU
• Description: Microcontroller with 64/128K Bytes of ISP Flash and USB Controller
• Manufacturer: ATMEL [ATMEL Corporation]

21.14 USB Software Operating modes
7593A–AVR–02/06
• 7-6 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 5 – STOI: Suspend Time-out Error Interrupt Flag
Set by hardware when a time-out error (more than 150 ms) has been detected after a suspend.
Shall be cleared by software. See for more details.
• 4 – HNPERRI: HNP Error Interrupt Flag
Set by hardware when an error has been detected during the protocol.
Shall be cleared by software. See for more details.
• 3 – ROLEEXI: Role Exchange Interrupt Flag
Set by hardware when the USB controller has successfully swapped its mode, due to an HNP
negotiation: Host to Device or Device to Host. Shall be cleared by software. See for more
details.
• 2 – BCERRI: B-Connection Error Interrupt Flag
Set by hardware when an error occur during the B-Connection. Shall be cleared by software.
• 1 – VBERRI: V-Bus Error Interrupt Flag
Set by hardware when a drop on VBus has been detected. Shall be cleared by software.
• 0 – SRPI: SRP Interrupt Flag
Set by hardware when a SRP has been detected. Shall be used in the Host mode only Shall be
cleared by software.
Depending on the USB operating mode, the software should perform some the following
operations:
Power On the USB interface
Bit
Read/Write
Initial Value
• Power-On USB pads regulator
• Wait USB pads regulator ready state
• Configure PLL interface
• Enable PLL
• Check PLL lock
• Enable USB interface
• Configure USB interface (USB speed, Endpoints configuration...)
• Wait for USB VBUS information connection
R
7
0
-
R
6
0
-
STOI
R/W
5
0
HNPERRI
R/W
4
0
ROLEEXI
R/W
3
0
BCERRI
R/W
2
0
VBERRI
AT90USB64/128
R/W
1
0
SRPI
R/W
0
0
OTGINT
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