蓝桥杯之单片机学习（十三）——IO扩展技术与存储器映射扩展的代码文件

#include <reg52.h> typedef unsigned int uint; typedef unsigned char uchar; void Delay(uint t) { while(t--); while(t--); } //配置HC138 void SelectHC138(uchar channel) { switch(channel) { case 4: //LED P2 = (P2 & 0X1F) | 0X80; break; case 5: //蜂鸣器和继电器 P2 = (P2 & 0X1F) | 0Xa0; break; case 6: //位码 P2 = (P2 & 0X1F) | 0Xc0; break; case 7: //段码 P2 = (P2 & 0X1F) | 0Xe0; break; case 0: //锁住所有寄存器 P2 = (P2 & 0X1F) | 0X00; break; } } void LEDRuning() { SelectHC138(4); //打开LED的HC138 P0 = 0XF0; Delay(60000); Delay(60000); P0 = 0X0F; Delay(60000); Delay(60000); P0 = 0XFF; Delay(60000); Delay(60000); } void SMGRuning() { uchar i; for(i = 0; i < 8; i++) { SelectHC138(6); P0 = 0X01 << i; SelectHC138(7); P0 = 0X00; Delay(60000); Delay(60000); } P0 = 0XFF; Delay(60000); Delay(60000); } void Initsys() { SelectHC138(5); P0 = 0X00;//关闭蜂鸣器和继电器 SelectHC138(4); P0 = 0XFF;//关闭LED } void main() { Initsys(); while(1) { LEDRuning(); SMGRuning(); } }