基于FPGA的高精度频率计设计
frequency函数计算频数摘  要
频率计是一种应用非常广泛的电子仪器，也是电子测量领域中的一项重要内容，而高精度的频率计的应用尤为广泛。目前宽范围、高精度数字式频率计的设计方法大都采用单片机加高速、专用计数器芯片来实现。传统的频率测量利用分立器件比较麻烦，精度又比较低，输入信号要求过高，很不利于高性能场合应用。
本论文完成了高精度数字频率计硬件设计和软件设计。该数字频率计主要包括FPGA和单片机两大部分。其中FPGA部分又可分为数据测量模块、FPGA和单片机接口模块、FPGA和数码管动态扫描部分。FPGA部分采用verilog语言编写了电路的各模块电路，选用了当前比较流行的EDA开发软件Quartus II作为开发平台，所有模块程序均通过了编译和功能仿真验证。对测频系统的设计流程、模型的建立和仿真做出了具体详细的研究，验证了该系统的正确性。单片机部分采用C51编写了控制软件。
本设计中以FPGA器件作为系统控制的核心，其灵活的现场可更改性，可再配置能力，对系统的各种改进非常方便，在不更改硬件电路的基础上还可以进一步提高系统的性能。
关键词：频率计，单片机，FPGA，电子设计自动化
Design of High-accuracy Digital Frequency Meter
Based on FPGA
ABSTRACT
Frequency meter is a kind of electronic instrument applied widely. A kind of high-accuracy digital frequency meter is designed based on FPGA in this paper. At present extends the scope, the high accuracy digital frequency meter's design method to use the monolithic integrated circuit to add, the special-purpose counter chip mostly to realize high speed.
The design of system hardware and system software is accomplished in the paper. System consists of FGPA and MCU. The circuit based on FPGA includes following some parts: data acquisition module, interface between FPGA and MCU, module scanning number tube. Every circuit module is realized by verilog.The platform of development is Quartus II and all modules procedure is demonstrated by compiling and simulation. Detailed research
of design flow, model establishment and system simulation is done. The correctness of the system is demonstrated. The software based on MCU is programmed by C51.
In this design takes the systems control by the FPGA component the core, its nimble scene alterability, may dispose ability again, is convenient to system's each kind of improvement, in does not change in hardware circuit's foundation also to be possible to further enhance system's performance.The system has the advantage of high-accuracy and convenience. It’s practicability of frequency meter is well.
KEY WORDS: Frequency meter, MCU, FPGA, electronic design automation