PIC 12F509 - 8Pin 4Mhz 1K
The PIC12F509 devices from Microchip Technology are low-cost, high-performance, 8-bit, fully-static, Flash-based CMOS microcontrollers. They employ a RISC architecture with only 33 single-word/single-cycle instructions. All instructions are single cycle (200 μs) except for program branches, which take two cycles.
High performance FLASH microcontroller that can be erased and reprogrammed without having to use a UV light source. This allows the same device to be used for prototype development as well as production. The 12F509 has 1k of code space, 41 bytes of RAM and 4Mhz Internal Oscilator.
Can work down to 2V!