1.用VHDL完成12位十进制数字频率计的设计及仿真。

2.频率测量范围：1Hz∼ 10KHz，分成两个频段，即1∼ 999Hz，1KHz∼ 10KHz，用三位数码管显示测量频率，用LED显示表示单位，如亮绿灯表示Hz，亮红灯表示KHz。

3.具有自动校验和测量两种功能，即能用标准时钟校验、测量精度。

4.具有超量程报警功能，在超出目前量程档的测量范围时，发出灯光和音响信号。

-1. VHDL design and simulation completed 12 decimal digits frequency meter. 2. Frequency measuring range: 1Hz~10KHz, divided into two bands, namely 1~999Hz, 1KHz~10KHz, with three digital display of measured frequency, with LED display showing the unit, such as a green light indicates Hz, red indicates KHz . 3. With automatic calibration and measurement two functions that use standard clock calibration, measurement accuracy. 4. With over-range alarm function when beyond the current range for the measuring range, emit light and sound signals.