The SN8PC21 is a RISC-like high performance and low operating voltage 8-bit micro-controller (2.0V~5.5V @0.5MIPS). One clock per instruction cycle (1T) architecture will provide up to 0.5MIPS computation power. The device is designed with the excellent IC structure including the program memory up to 1K-word OTP ROM, data memory of 32-bytes RAM, one 8-bit timer counters (T0), a watchdog timer, one interrupt sources (T0), one channel duty/cycle programmable IR output (IROUT) with 400mA sunk current at 3V and 4-level stack buffers. There are four oscillator configurations to select for generating system clock, including High/Low Speed crystal, ceramic resonator or cost-saving RC. This device also includes an internal 8MHz RC oscillator for system clock.