3位BCD码的计数显示电路。BCD码计数电路从0计到9然后返回到0从新计数。3位BCD码计数器可以实现从0到999的十进制计数。要将计数过程用七段显示LED数码管显示出来，这里采用动态分时总线切换电路对数码管进行扫描，对数码管依次分时选中进行输出计数的个、十、百位的数据。-3 BCD code count display circuit. BCD code counting circuit count from 0 to 9 and then back to 0 from the new count. 3 BCD code counter can be achieved from 0 to 999 decimal count. Counting process with seven segment displays to LED digital tube displays, where dynamic time-sharing digital bus switch circuit to scan, followed by time-sharing of digital output selected for a count of ten, hundred bits of data.