The ML7012-04 is a single chip modem LSI device that enables data communication conforming to ITU-T recommendations V.22bis, V.22, and V.21. This device is equipped with the error correction protocol function conforming to MNP Class 4. (The MNP Class 4 can be used for V.22bis or V.22.) The ML7012-04 consists of high speed DSP, analog front end, and digital logic circuit. In addition, this device provides local analog loop testing, synchronous/asynchronous switching, dialing, and auto answering functions. The ML7012-04 has a serial interface as an external interface. When integrated into the system, it is controlled from a control CPU through a serial interface (e.g. UART). By connecting a level converter, the ML7012-04 can easily implement a modem that can be controlled through the RS-232C interface.