在电子领域内，频率是一种最基本的参数，并与其他许多电参量的测量方案和测量结果都有着十分密切的关系。由于频率信号抗干扰能力强、易于传输，可以获得较高的测量精度。因此，频率的测量就显得尤为重要，测频方法的研究越来越受到重视。

　　频率计作为测量仪器的一种，常称为电子计数器，它的基本功能是测量信号的频率和周期频率计的应用范围很广，它不仅应用于一般的简单仪器测量，而且还广泛应用于教学、科研、高精度仪器测量、工业控制等其它领域。在数字电路中，数字频率计属于时序电路，它主要由具有记忆功能的触发器构成。在计算机及各种数字仪表中，都得到了广泛的应用。在CMOS电路系列产品中，数字频率计时量程最大、品种很多的产品，是计算机、通讯设备、音频视频的科研生产领域不可缺少的测量仪器，并且与许多电参量的测量方案、测量结果都有十分密切的关系。因此，频率的测量就显得更为重要。

本设计设计6位十六进制频率计，以触发器和计数器为核心，由信号输入、触发、计数、数据处理和数据显示等功能模块组成。本次采用QuartusII的宏元件和VHDL语言设计两种方法来设计6位十六进制频率计，提高了测量频率的范围。

-In the electronics field, the frequency is a basic parameter, and with many other electrical parameters of the measurement program and the measurement results have a very close relationship. Since the frequency signal anti-interference ability, easy to transport, you can get higher accuracy. Therefore, the frequency of measurement is particularly important, frequency measurement method of getting attention.

Frequency meter as a measuring instrument, often referred to as electronic counter, and its basic function is to measure the signal frequency and cycle frequency meter wide range of applications, it is not only used simple instruments to measure the general, but also widely used in teaching , scientific research, high-precision instrumentation, industrial control and other areas. In digital circuits, digital frequency meter are sequential circuits, it is mainly the trigger memory function by a composition. In the computer and various digital instruments, have been widely used. Prod