The EM91220 is a series of tone/pulse switchable dialers that is composed of T/P dialer and T/P dialer with 20-set memories . The EM91220 series provides necessary functions of telephone set for application in any environment, such as Pulse dialing, Tone (DTMF) dialing, Handfree dialing, keying tone , mute and pulse mute functions. Beside this, SDO (Serial Data Output) functions is provided in advance version that is designed to drive LCD driver and voice synthesizer. In this application, the dialing numbers can be displayed on LCD screen with EM32100 ( or EM32116 ).