Protues仿真实例（8051）-8255并行口扩展.rar

#include<regx52.h> #include<intrins.h> #include<absacc.h> #define uchar unsigned char #define uint unsigned int #define PA XBYTE[0x3fff] #define PB XBYTE[0x7fff] #define PC1 XBYTE[0xbfff] #define CTL XBYTE[0xffff] sbit reset=P2^5; void delay(uchar t); void display(); void main() { EA=1; ET0=1; TMOD=0x01; reset=1; _nop_(); reset=0; CTL=0x80; //写8255控制字，设置PA,PB,PC为输出口 while(1) { display();} } void display() { uchar outdata=0xfe,i; for(i=0;i<8;i++) {PA=outdata; delay(200); outdata=_crol_(outdata,1); } PA=0xff; outdata=0xfe; for(i=0;i<8;i++) {PB=outdata; delay(200); outdata=_crol_(outdata,1);} PB=0xff; outdata=0xfe; for(i=0;i<8;i++) {PC1=outdata; delay(200); outdata=_crol_(outdata,1);} PC1=0xff; } void delay(uchar t) { for(;t>0;t--) { TH0=(65536-1000)/256; TL0=(65536-1000)%256; TR0=1; while(TF0==0) ; TF0=0; } TR0=0; }