前言数字计数器几乎在每一个数字系统中都能遇到,它们可由分立元件或集成电路的触发器组成。电路结构虽简单,但它们的输出却不易被人们直观地了解,例如常见的十进制计数器,其输出是二进制编码的十进制形式。在频率测量、激光测距等应用中,常常希望将测得的结果以人们熟悉的十进制数直接显示出来,因此须设法把计数器输出转换 Foreword Digital counters are encountered in almost every digital system, and they may consist of discrete components or flip-flops of an integrated circuit. Although the circuit structure is simple, but their output is not easy for people to intuitively understand, such as the common decimal counter, the output is binary coded decimal form. In applications such as frequency measurement, laser ranging, etc., it is often desirable to display the measured result directly in familiar decimal numbers, so that it is necessary to try to convert the counter output