如何利用8255扩展单片机的IO口呢

8255总线实验编写程序利用8255扩展单片机的IO口，控制8位数码管显示1-8。程序：#include#include#define PORT_A XBYTE[0X7FFC]#define PORT_B XBYTE[0X7FFD]#define PORT_C XBYTE[0X7FFE]#define PORT_CTL XBYTE[0X7FFF]void delay(){unsigned int i;for(i=0;i