ATMEGA8单片机频率计程序。原理上采用32.768K外部晶振产生异步时钟信号 ，作为M8定时器2de时钟源，设定1024de预分频，可以得到TCNT2溢出de精确时间为1s，在溢出中断时控制74ls00与非门进而控制被测信号de通断，累计1s 内计数器获得de值，经过简单de运算则可获得被测信号de频率-ATMEGA8 MCU frequency meter program. Principle produced by 32.768K asynchronous external crystal clock signal, as the M8 2de clock timer, set 1024de prescaler, can get accurate time TCNT2 overflow de 1s, in the overflow interrupt control 74ls00 then control the NAND gate measured signal de-off, the cumulative gain de 1s in the counter value is obtained after a simple de op de frequency of the signal