This part is a kind of semiconductor called ATxmega256A3BU.
Function of this product has 8/16-bit Atmel XMEGA A3BUMicrocontroller.
Manufacturers : Atmel
Image and pinout :
Some of the text within the PDF file :
Features 8/16-bit Atmel XMEGA A3BUMicrocontroller ATxmega256A3BU z High-performance, low-power Atmel®AVR®XMEGA® 8/16-bit Microcontroller z Nonvolatile program and data memories z 256KBytes of in-system self-programmable flash z 8KBytes boot section z 4KBytes EEPROM z 16KBytes internal SRAM z Peripheral features z Four-channel DMA controller z Eight-channel event system z Seven 16-bit timer/counters z Four timer/counters with four output compare or input capture channels z Three timer/counters with two output compare or input capture channels z High resolution extension on all timer/counters z Advanced waveform extension (AWeX) on one timer/counter z One USB device interface z USB 2.0 full speed (12Mbps) and low speed (1.5Mbps) device compliant z 32 Endpoints with full configuration fl [ ... ]