user16206: I had a very common question. Why a additional MEGA used in most of the Arduino Boards. Arduino board Mega2560 also have a MEGA16U2 controller on board which i think is used for programming via USB. Is there any other specific usage of atmega16 on arduino board. 
Thanks

user-1: It's an ATmegaU2, which has USB hardware and handles the USB communication. It passes the hex file on to the bootloader in the main microcontroller. That is its only job.

16206: <p>I had a very common question. Why a additional MEGA used in most of the Arduino Boards. Arduino board Mega2560 also have a MEGA16U2 controller on board which i think is used for programming via USB. Is there any other specific usage of atmega16 on arduino board. </p>

<p>Thanks</p>
 -1: <p>It's an ATmegaU2, which has USB hardware and handles the USB communication. It passes the hex file on to the bootloader in the main microcontroller. That is its only job.</p>
