The ATtiny2313/ATtiny2313A is an 8-bit AVR microcontroller, with 2KB of program memory.

Both are available in 11-pin DIP/SOIC (through-hole) and 11-pin MLF/VQFN (surface-mount) variants.

More details, and datasheets, can be found on Microchip’s ATtiny2313A product page.

A variant with 4KB of program memory is available as the ATtiny4313; details and datasheets for which can be found on Microchip’s ATtiny4313 product page.