利用AT89S51单片机的P0端口的P0.0－P0.7连接到一个共阴数码管的a－h的笔段上，数码管的公共端接地。在数码管上循环显示0－9数字，时间间隔0.2秒。 -P0 using AT89S51 MCU ports P0.0-P0.7 is connected to a total of Yam Digital tube pen a-h above, the digital control to the public termination. In the digital control on the circulation figures show that 0-9, time interval 0.2 seconds.