练习一I/O控制 练习目的:1.掌握单片机I/O口控制方法。2.掌握Keil与Proteus的使用方法。练习内容：参考例程，掌握Keil与Proteus的联调使用方法。画出电路，编写一段程序，用P1 口作为控制端口，使8个LED 轮流亮。画出电路，编写一段程序，用P1.0~P1.6 口控制LED，P1.7 控制LED 的亮和灭(P1.7 接按键，按下时LED 亮，不按时LED 灭。)-Exercise I/O control, practice the purpose of a master MCU I/O port control method. Master the use of the Keil and Proteus. Practice reference routines, master the use of the Keil and Proteus FBI. Reference routines, master MCU I/O port control method. Draw the circuit, write a program, as a control port P1 port the 8 LED turns bright. 4. Draw the circuit, write a program, P1.0 to P1.6 port control LED P1.7 control the LED turn on and off (P1.7 access keys, when pressed LED lights, LED off on time.)