Arduino UNO R3 Product Reference Manual page 2

Features
ATMega328P Processor
Memory
AVR CPU at up to 16 MHz
32KB Flash
2KB SRAM
1KB EEPROM
Security
Power On Reset (POR)
Brown Out Detection (BOD)
Peripherals
2x 8-bit Timer/Counter with a dedicated period register and compare channels
1x 16-bit Timer/Counter with a dedicated period register, input capture and compare channels
1x USART with fractional baud rate generator and start-of-frame detection
1x controller/peripheral Serial Peripheral Interface (SPI)
1x Dual mode controller/peripheral I2C
1x Analog Comparator (AC) with a scalable reference input
Watchdog Timer with separate on-chip oscillator
Six PWM channels
Interrupt and wake-up on pin change
ATMega16U2 Processor
8-bit AVR® RISC-based microcontroller
Memory
16 KB ISP Flash
512B EEPROM
512B SRAM
debugWIRE interface for on-chip debugging and programming
Power
2.7-5.5 volts
2 / 13 Arduino® UNO R3 / Rev. 01 - 25/11/2021
Arduino® UNO R3