Encoding and Decoding of DTMF Signal Based on DSP

D156-tone multi-frequency (DTMF) Signals are used in touch-tone telephones as well as many other areas. The design method of the traditional DTMF signal encoding and decoding circuit is more complex and the number of chip is more much that easy to cause the system unstable. The encoding and decoding of DTMF signal based on digital signal processor (DSP) not only can improve the real-time performance of DTMF signal processing, but also streamline the entire system module. In paper using TMS320vf5402 as the hardware platform and CCS as the software platform and programming in asm language, the encoding and decoding of DTMF signal are realized. The Goertzel optimization algorithm is used to reduce the computational complexity in the decoding part. The experimental results show that the encoding and decoding of DTMF signal based on DSP makes the signal processing system more simple and flexible.