ML7204和PicoBlaze软核处理器实现低速话音编解码系统

语音信号压缩编码是数字语音信号处理的主要方面．在现有的语音编码中，G．729A算法在8kb／s的码率下取得了较好的语音质量，具有广阔应用前景，因此提出采用PicoBlaze和ML7204实现G．729A语音压缩／解压详细的软硬件实现方案，并描述了G．729A语音编解码器ML7204的工作原理、性能、接口，以及FPGA内嵌IP核微处理器PicoBlaze的特点和使用方法。给出硬件电路设计原理，以及各部分的具体实现方法和原理图。并给出软件流程和主要代码。实验结果表明，系统提供话音点到点的时延仅为25mS，而语音质量平均意见MOS值达到4．2。在可懂度和清晰度等性能优异，该系统设计可应用于无线移动网、数字多路复用系统和计算机通信系统。

Low-bit-rate voice COEDC system based on ML7204 and microprocessor IP core PicoBlaze

Digital speech communication is the most widely popular business in the current information industry. Compression and coding of the speech signal is one direction of the digital speech signal processing. In the existing speech coding, the G.729A algorithm in the 8kh/s bit rate has achieved better voice quality and has broad application prospects. In this paper, it described a G.729A codec chip ML7204 with its principle,performance,interface and so on, and then described the FPGA embedded processor IP core PieoBlaze, with its characteristics and usage. Finally it proposed the realization of G.729A voice compression/decompression hardware and software implementations in detail with PicoBlaze and ML7204. On the hardware side,it gave the hardware circuit design principles,as well as part of the concrete implementation and schematic diagrams. On the software side ,it gave the overall software flow chart and the main code. Experimental results show that the system provides point-to-point voice latency only 25ms,while the voice MOS value reaches 4.2.The intelligibility and clarity of the system voice are perfect. It is used in wireless mobile networks,digital mnhiplexing systems and computer communications systems.