Atmel ATMEGA32U4-AUR SMD IC

The ATmega16U4/ATmega32U4 provides the following features: 16/32K bytes of In-System
Programmable Flash with Read-While-Write capabilities, 512Bytes/1K bytes EEPROM,
1.25/2.5K bytes SRAM, 26 general purpose I/O lines (CMOS outputs and LVTTL inputs), 32
general purpose working registers, four flexible Timer/Counters with compare modes and PWM,
one more high-speed Timer/Counter with compare modes and PLL adjustable source, one
USART (including CTS/RTS flow control signals), a byte oriented 2-wire Serial Interface, a 12- channels 10-bit ADC with optional differential input stage with programmable gain, an on-chip
calibrated temperature sensor, a programmable Watchdog Timer with Internal Oscillator, an SPI
serial port, IEEE std. 1149.1 compliant JTAG test interface, also used for accessing the On-chip
Debug system and programming and six software selectable power saving modes. The Idle
mode stops the CPU while allowing the SRAM, Timer/Counters, SPI port, and interrupt system
to continue functioning. The Power-down mode saves the register contents but freezes the
Oscillator, disabling all other chip functions until the next interrupt or Hardware Reset. The ADC
Noise Reduction mode stops the CPU and all I/O modules except ADC, to minimize switching
noise during ADC conversions. In Standby mode, the Crystal/Resonator Oscillator is running
while the rest of the device is sleeping. This allows very fast start-up combined with low power
consumption.

Datasheet available here.