基于FPGA的数字频率计的设计和实现

Construction and Realization of the Digital Cymometer Based on FPGA

现场可编程门阵列的出现给现代电子设计带来了极大的方便和灵活性,使复杂的数字电子系统设计变为芯片级设计,同时还可以很方便地对设计进行在线修改。本文以设计一个四位显示的十进制数字频率计为例,介绍了在一片FPGA芯片上实现多位数字频率计的设计方法和实现步骤,并且给出了仿真结果。在设计中,所有频段均采用直接测频法对信号频率进行测量,克服了逼近式换挡速度慢的缺点。所设计的电路通过硬件仿真,下载到目标器件上运行,能够满足实际测量频率的要求。

The appearance of FPGA(Field Programmable Gate Array)leads to the convenience and flexibility of the modern electronic construction,which changes the complicated digital electronic system construction into the onchip construction.On the other hand,it can also make some online modification expediently.With a case which describes an quadbit shown on the decimal digital frequency,the author introduces the construction method and the realization steps on a single FPGA chip.The author shows an emulational result.During the construction process,the signal frequency of all the Frequency Channel is measured by the way of direct measurement,which overcomes the shortcoming of low approximate shift speed.With the certification of the hardware emulation system,the circuit constructed can meet the demand of measuring frequency in the reality,which has some theoretic and practical signification.