The SN8P2521 is a RISC-like high performance, low power consumption and industrial class 8-bit micro-controller. The device is designed with the excellent IC structure including the program memory up to 2K-word OTP ROM, data memory of 256 bytes RAM, two 8-bit timer counters (T0, TC1), eight channel PWM output (TC0), a watchdog timer, six interrupt sources (T0, TC1, INT0, CM0, SIO, MSP), one channel 8-bit duty/cycle programmable PWM output (PWM1), 12-channel comparator, one SIO interface, one MSP slave mode interface and 8-level stack buffers. There are two oscillator configurations to select for generating system clock, including an internal 16MHz RC oscillator for system clock and an internal low frequency RC oscillator for slow mode controlled by programming.