中文摘要：

设计一个基于DSP和DDS芯片的新型气体浓度检测系统。DSP是整个系统的核心，主要完成DDS芯片控制时序的产生，专用A／D采样控制以及片外部FLASH和SDRAM存储芯片控制，并通过串口与上位机通信。讨论了DSP与主要模块之间的接口通信方案，以及在DSP内部实现时域信号自相关运算，改善了信噪比。实验证明，该系统很好地满足了气体浓度检测的要求，可以用于多种气体的检测。

英文摘要：

A new type gas concentration detection system based on DSP chip and DDS technology is designed. DSP is core of the system. The generation of control sequence of DDS and the sampling control of A / D chip are completed by DSP. The external memory chips FLASH and SDRAM are configured by DSP. The PC communication is achieved through the serial ports. The communication between DSP and main modules interface are discussed and auto - correlation algorithm of time - domain signal is designed and realized in the DSP, which effectively improve the SNR. The experimental results show that the system meets the requirement and can be applied to many different gases detection.