ML7084 is the processor being used for IP telephone and VoIP gateway. By adding memory and ancillary equipment, can compose VoIP system simplely. At the same time, if wanting to be added the VoIP function , ML7204 by the route implement having already used a processor is the most suitable weave the decoder chip. Besides, integrated echo of that chip removes an implement , an audible signal telephone set's such as checking and communicating by phone three method must prepare for a function.