摘 要本论文介绍了基于 FPGA 的多通道采样系统的设计。用 FPGA 设计一个多通道采样控制器，利用 VHDL 语言设计有限状态机来实现对 AD7892 的控制。由于 FPGA 器件的特性是可以实现高速工作，为此模拟信号选用音频信号。由于音频信号的频率是20Hz-20KHz,这样就对 AD 转换的速率有很高的要求.因为 FPGA 的功能很强大，所以我们把系统的许多功能都集成到 FPGA 器件中，例如 AD 通道选择部分，串并输出控制模块，这样使得整个系统的外围电路简单、系统的稳定性强。FPGA 的配置模式选用被动串行模式，这样就增强了系统的可扩展性。输出模式可选择性使得系统的应用相当广泛，串行输出可以用于通信信号的采集，方便调制后发射到远程接受端，远程接收端对采集的数据进行解调；而并行输出模式则可以通过高速存储器将采集的信号放到微机或者其他的处理器上，根据采集的数据进行相应的控制。此系统的缺点是由于 FPGA器件配置是基于 SRAM 查找表单元，编程的信息是保持在 SRAM 中，但 SRAM 在掉电后编程信息立即丢失，所以每次系统上电都需要重新配置芯片，这对在野外作业的工作人员很不方便，解决的方法是专用的配置器件来配置 FPGA，在每次系统上电的时候会自动把编程信息配置到 FPGA 芯片中。但设计中没有采用到这种配置方案主要是考虑到专用配置器件的价格问题。本文开始介绍了多通道系统的组成部分，然后分别介绍了各个组成部分的原理和设计方法,其中重点介绍了FPGA软件设计部分。还对当前十分流行的基于FPGA的设计技术作了简单的阐述，最后对系统的调试和应用作了简短的说明。关键词：音频放大；滤波器；FPGA；VHDL；AD7892；有限状态机；AbstractThe paper introduces the design of multiple channel sampling system based on FPGA, It designs a multiple channel control sampling instrument with FPGA, I use VHDL to design ASM and then achieve the control to AD7892. Because the FPGA device can work in high-speed, we select audio signal for analog signals. The range of audio signal frequency is 20Hz-20 KHz, And then the transform speed of AD sampling must be very high. We integrate many modules in the FPGA device. For example the AD sampling channel control, the mode of output which made the circuit simply and the system stably. We choose Passive Serial for configuring the FPGA device which made the system can extend easily. The mode of output can control which made this system can use many field. The serial output mode can use in the sampling of communication. The sampling data can launch to the long-distance sink by brewage, and then the long-distance sink can demodulation the sampling data. The parallel output mode can put the sampling data to the microprocessor or other processor by the high-speed memorizer. And then control accordingly. The disadvantage of this system is that the configure of the FPGA device is based on SRAM LUT. The message of programming is kept in the SRAM, which will lose when the system is out of power supply. So we should reconfigure the programming message into the FPGA device when the system has the power supply again. It is not very convenience for working outside. But this can be resolve by using appropriative configure device which can load the configure message into the FPGA device automatically when the system have power supply. Because the price of the appropriative...
