1F3, Atmel ATMega32U4 8-bit microcontroller. Looks like a newer process than the old 2003-vintage AVRs, maybe 250nm instead of 350?
Looks like flash top center, oscillator bottom center, then SRAM and EEPROM in the lower left with analog stuff in the top left.
The logo says Atmel Nantes, so I guess we know which Atmel office did the layout here!