The HT95LXXX family MCU are 8-bit high performance RISC-like microcontrollers with built-in DTMF generator and dialer I/O which provide MCU dialer implementation or system control features for telecom product applications. The phone controller has a built-in program ROM, data RAM, LCD driver and I/O lines for high end products design. In addition, for power management purpose, it has a built-in frequency up conversion circuit (32768Hz to 3.58MHz) which provides dual system clock and four types of operation modes. For example, it can operate with low speed system clock rate of 32768Hz in green mode with little power consumption. It