ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 265

• Manufacturer Part Number: ATmega32U4
• Manufacturer: Atmel Corporation

Specifications of ATmega32U4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 14
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 26
• Ext Interrupts: 13
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 3.3
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 12
• Input Capture Channels: 2
• Pwm Channels: 8
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

21.13 USB Software Operating modes
7766F–AVR–11/10
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
ATmega16/32U4
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