摘要
论述了利用单片机取代工控PC机进行石英晶体频率检测分选的技术。石英晶体的振荡信号经过整形,分频,放大达到数字电路芯片要求的TTL电平标准后输入到CPLD(Xilinx95108),CPLD在单片机的控制下同时对输入信号和标准频率源信号计数。单片机控制计数的时间,到时后读出两者数值。它们的比值再乘以标准频率就是被测信号频率。系统结构简单,运行稳定,测量精度高。静态测频误差<400Hz,相对误差<10ppm。
Discussed a technology to measure quartz crystal frequency using SCM 8051 instead of traditional ways of using PC. The original surge signal traverses shaping, demultiplying and amplifying, then is inputed to the CPLD. At the same moment, CPLD counts the inputed crystal frequency signal and the standard signal. When the counting time comes to the end, 8051 computes their quotient. The quotient multiplies by the standard frequency is the terminal measure results. By this means, the absolute measure mistake is below 400 Hz, relative mistake is below 10ppm.
出处
《微机发展》
2004年第4期38-39,42,共3页
Microcomputer Development
