
In digital circuits, digital frequency of a timing circuit, it is mainly by the memory of a flip-flop. In the computer and digital instrumentation, have been widely used. CMOS circuitry in the series, the number of frequency of usage is greatest, many varieties of products, computers, communications equipment, audio and video, and other areas of scientific research and production of an indispensable instrument, and with many parameters, the measurement programme, the measurement results are Very close relationship, therefore, the frequency of measurement becomes more important.
Is a digital frequency of use decimal figures show that the number of measured frequency - measuring instruments. Under normal circumstances, the use of oscilloscope measurements can be roughly measured the frequency signal, accurate measurement of digital frequency is used. Its basic function is to measure the sine signal, square-wave signals, a sharp pulse of time and various other units within the physical changes, it uses a very wide range.