The MSM7718, developed for PHS (Personal Handyphone System) applications, is a CMOS LSI device and contains a line echo canceler and a single channel full-duplex ADPCM transcoder that performs interconversion between voice-band analog signal and 32 kbps ADPCM data. This device includes DTMF tone and several types of tone generation, transmit/receive data mute and gain control, and VOX function and is best suited for master telephones in PHS applications.