This chip is the Atmega328, a 32 KB microcontroller. It is the MCU found on the Arduino Duemilanove.  This chip is versatile and can be applied to many different projects.

• Data Bus Width:   8 bit
• Program Memory Type:  Flash
• Program Memory Size:  32 KB
• Data RAM Size:  2 KB
• Interface Type:  2-Wire/SPI/USART
• Maximum Clock Frequency:  20 MHz
• Number of Programmable I/Os:  23
• Number of Timers:  3
• Maximum Operating Temperature:  + 85 C
• Minimum Operating Temperature:  - 40 C
• On-Chip ADC:  6-ch x 10-bit