A wideband Voice over Internet Protocol (VoIP) terminal is provided. The wideband VoIP terminal includes a synchronous serial interface which processes audio data input thereto or output therefrom in series in synchronization with a clock; and an audio accelerator which encodes or decodes the audio data, wherein the synchronous serial interface includes a buffer buffering the audio data and a buffer controller controlling the buffer and the audio accelerator includes a memory storing the audio data processed by the synchronous serial interface under the control of the buffer controller, a memory controller controlling the memory and an encoder/decoder encoding/decoding the audio data. The wideband VoIP terminal can facilitate the input and output of data.