Among electronic technology, frequency is one of the most basic parameters, and result of measuring have a very close relation to a lot of electric parameters, so the measurement of frequency seems even more important. In order to realize the counting of intellectuality examines frequently, realize a wide-range, high-accuracy cymometer, an effective method is to use one-chip computer for the design of the cymometer. This subject recommends regarding 51 Single-Chip computer as the key device, include signal input, signal amplify, signal choose, clock offer, data person who reveal function digital design method of cymometer of module still in addition. The hardware circuit of the cymometer is drawing with Protel mapping software, the one-chip computer control procedure of the software part, wrote the assembler language. Because originally design the design method to adopt module, improve the range of measuring frequency.
Key words: Measurement, Cymometer, Single-Chip computer