摘要
激光雷达的发射波及回波信号经光电器件转换形成的电信号具有脉宽窄,幅度低,背景噪声大等特点,对其进行低速数据采集存在数据精度不高等问题。同时,A/D转换器与数字信号处理器直接连接会导致数据传输不及时,影响系统可靠性、实时性。针对激光雷达回拨信号,提出基于FPGA与DSP的高速数据采集系统,利用FPGA内部的异步FIFO和DCM实现A/D转换器与DSP的高速外部存储接口(EMIF)之间的数据传输。介绍了ADC外围电路、工作时序以及DSP的EMIF的设置参数,并对异步FIFO数据读写进行仿真,结合硬件结构详细地分析设计应注意的问题。系统采样率为30MHz,采样精度为12位。
Laser radar echo signal converted by photoelectric conversion has the characteristics of narrow pulse width, low amplitude and high background noise. The accuracy of the signal would not be high when using low speed data acquisition. Meanwhile, connecting the digital signal processor to A/D converter directly would lead to the not-timely data transfer, and affect system＇s reliability and real-time. This paper proposed a high-speed data acquisition system based on FPGA and DSP aiming at the laser radar echo signal. The data transfer between A/D eonverter and the high-speed external memory interface （EMIF） of DSP was achieved by using FPGA internal asynchronous FIFO and DCM. The peripheral circuit, timing sequence of ADC and the parameters of EMIF were described, and the timing of writing and reading FIFO was simulated. The key points of the hardware design were also proposed. The sample rate of system is 30MHz, and resolution is 12bits.
出处
《电子设计工程》
2010年第12期159-161,共3页
Electronic Design Engineering
