Datasheet

261
7593L–AVR–09/12
AT90USB64/128
2 – BCERRI: B-Connection Error Interrupt flag
Set by hardware when an error occur during the B-Connection (that is, if Peripheral has not con-
nected after 300ms of Vbus delivery request). 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 softw are.
22.13 USB Software Operating modes
Depending on the USB operating mode, the software should perform some the following
operations:
Power On the USB interface
•Power-On USB pads regulator
Configure PLL interface
Enable PLL and wait PLL lock
Enable USB interface
Configure USB interface (USB speed, Endpoints configuration...)
Wait for USB VBUS information connection
Attach USB device
Power Off the USB interface
Detach USB interface
Disable USB interface
Disable PLL
Disable USB pad regulator
Suspending the USB interface
Clear Suspend Bit
Freeze USB clock
Disable PLL
Be sure to have interrupts enable to exit sleep mode
Make the MCU enter sleep mode
Resuming the USB interface
•Enable PLL
Wait PLL lock
Unfreeze USB clock
Clear Resume information