atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 284

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

22.11 USB Software Operating modes
284
ATmega32U4
Depending on the USB operating mode, the software should perform some the following
operations:
Power On the USB interface
Power Off the USB interface
Suspending the USB interface
Resuming the USB interface
• Power-On USB pads regulator
• Configure PLL interface
• Enable PLL
• Check PLL lock
• Enable USB interface
• Configure USB interface (USB speed, Endpoints configuration...)
• Wait for USB VBUS information connection
• Attach USB device
• Detach USB interface
• Disable USB interface
• Disable PLL
• Disable USB pad regulator
• Clear Suspend Bit
• Freeze USB clock
• Disable PLL
• Be sure to have interrupts enable to exit sleep mode
• Make the MCU enter sleep mode
• Enable PLL
• Wait PLL lock
• Unfreeze USB clock
• Clear Resume information
7766A–AVR–03/08