Features
• High Performance, Low Power AVR® 8-Bit Microcontroller
• Advanced RISC Architecture
– 135 Powerful Instructions
– Most Single Clock Cycle Execution
– 32 x 8 General Purpose Working Registers
– Fully Static Operation
– Up to 16 MIPS Throughput at 16 MHz
– On-Chip 2-cycle Multiplier
• Non-volatile Program and Data Memories
– 16/32K Bytes of In-System Self-Programmable Flash
(ATmega16U4/ATmega32U4)
– 1.25/2.5K Bytes Internal SRAM (ATmega16U4/ATmega32U4)
– 512Bytes/1K Bytes Internal EEPROM (ATmega16U4/ATmega32U4)
– Write/Erase Cycles: 10,000 Flash/100,000 EEPROM
– Data retention: 20 years at 85°C/ 100 years at 25°C(1)
– Optional Boot Code Section with Independent Lock Bits
In-System Programming by On-chip Boot Program
True Read-While-Write Operation
All supplied parts are preprogramed with a default USB bootloader
– Programming Lock for Software Security • JTAG (IEEE std. 1149.1
compliant) Interface
– Boundary-scan Capabilities According to the JTAG Standard
– Extensive On-chip Debug Support
– Programming of Flash, EEPROM, Fuses, and Lock Bits through the
JTAG Interface
• USB 2.0 Full-speed/Low Speed Device Module with Interrupt on
Transfer Completion
– Complies fully with Universal Serial Bus Specification Rev 2.0
– Supports data transfer rates up to 12 Mbit/s and 1.5 Mbit/s
– Endpoint 0 for Control Transfers: up to 64-bytes
– 6 Programmable Endpoints with IN or Out Directions and with Bulk,
Interrupt or Isochronous Transfers
– Configurable Endpoints size up to 256 bytes in double bank mode
– Fully independent 832 bytes USB DPRAM for endpoint memory
allocation
– Suspend/Resume Interrupts
– CPU Reset possible on USB Bus Reset detection
– 48 MHz from PLL for Full-speed Bus Operation
– USB Bus Connection/Disconnection on Microcontroller Request
– Crystal-less operation for Low Speed mode
• Peripheral Features
– On-chip PLL for USB and High Speed Timer: 32 up to 96 MHz
operation
– One 8-bit Timer/Counter with Separate Prescaler and Compare Mode
– Two 16-bit Timer/Counter with Separate Prescaler, Compare- and
Capture Mode
– One 10-bit High-Speed Timer/Counter with PLL (64 MHz) and Compare
Mode
– Four 8-bit PWM Channels
– Four PWM Channels with Programmable Resolution from 2 to 16 Bits
– Six PWM Channels for High Speed Operation, with Programmable
Resolution from 2 to 11 Bits
– Output Compare Modulator
– 12-channels, 10-bit ADC (features Differential Channels with
Programmable Gain)
– Programmable Serial USART with Hardware Flow Control
– Master/Slave SPI Serial Interface
