This part is a kind of semiconductor called ATMEGA328A.

Function of this product has 8-bit Microcontroller SUMMARY.

Manufacturers : Atmel

Image and pinout :

Some of the text within the PDF file :

Atmel 8-bit Microcontroller with 4/8/16/32KBytes InSystem Programmable Flash ATmega48A; ATmega48PA; ATmega88A; ATmega88PA; ATmega168A; ATmega168PA; ATmega328; ATmega328P SUMMARY Features • • High Performance, Low Power Atmel®AVR® 8-Bit Microcontroller Family Advanced RISC Architecture – 131 Powerful Instructions – Most Single Clock Cycle Execution – 32 x 8 General Purpose Working Registers – Fully Static Operation – Up to 20 MIPS Throughput at 20MHz – On-chip 2-cycle Multiplier High Endurance Non-volatile Memory Segments – 4/8/16/32KBytes of In-System Self-Programmable Flash program memory – 256/512/512/1KBytes EEPROM – 512/1K/1K/2KBytes Internal SRAM – Write/Erase Cycles: 10,000 Flash/100,000 EEPROM – Data retention: 20 years at 85C/100 years at 25C(1) [ ... ]

ATMEGA328A PDF Datasheet Download