Implementation And Optimization Of The Codec In The IP Phone Terminal Based On MCF5249

IP Phone is a popular communication method that realizes voice communication through Internet. Taking advantage of low cost, and with the development of Internet techniques, it has been getting more and more attention. A solution of IP phone terminal based on ColdFire V2 core is presented in this paper, and G.723.1 codec is implemented and optimized on M5249C3 board. MCF5249 microprocessor integrates an enhanced multiply-accumulate unit (eMAC) operating at 140MHz. The eMAC has a single-clock issue for 32 32-bit multiplication instrucions and implements a four-stage execution pipeline. In some cases, it can replace MCU+DSP to make the design easy and reduce the cost. ITU-T Recommendation G.723.1 is about a dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3kbit/s, and is applied broadly in IP phone and mobile communication.×The difficulties in this paper are that the algorithm used in G.723.1 is complex and the instruction set of ColdFire is less than DSP. The codec based on G.723.1 is implemented and optimized according to specialities of ColdFire architecture, and then transformed toμClinux OS. Now the optimized codec can make real time communication.