SN8P2839 is a high-performance 8-bit microcontroller with the 24K-word of the OTP ROM. The SN8P2839 provides the following features: 2048 bytes of RAM, 6-timer function(T0,T1,T2,T3,TC0,TC1), a watchdog timer, 9-sources internal interrupts (T0,T1,T2,T3,TC0,TC1,ADC,SIO,UART),8-channel 12-bit ADC, two PGIA, three voltage regulator, a R-Type LCD driver for 4-common x 36segments, 16-level stack register. In addition, the SN8P2839 is a dual clock system, i.e. high-speed system clock and low-speed system clock. The high-speed system clock sources is generated from internal 16MHz high-speed RC oscillator (IHRC 16MHz). The low-speed system clock is generated from external Low Clock: Crystal type 32.768KHz.