The MSM7731 is an LSI device developed for portable, handsfree communication with built-in line echo canceler, acoustic echo canceler, and transmission signal noise canceler. Built-in to the voice signal interface is a linear CODEC for the analog interface on the acoustic-side, and a linear CODEC for the analog interface on the line-side. On the line-side, in addition to the analog interface, there is also a m-law PCM/16-bit linear digital interface. Equipped with gain and mute controls for data transmission and reception, a m-law PCM/16bit linear digital interface for memo recording and message output, and transfer clock and sync clock generators for digital communication, this device is ideally suited for a handsfree system.