基于51和Protues仿真的82C55A 软件模拟读写时序

仿真图：

源代码：

/***************   writer:shopping.w   ******************/#include <reg52.h>#include <absacc.h>#define uint unsigned int#define uchar unsigned char//#define PA XBYTE[0x0000] //#define PB XBYTE[0x0001]//#define PC XBYTE[0x0002]//#define COM XBYTE[0x0003]#define ADDR_CMD              0x03#define ADDR_A_PORT           0x00#define ADDR_B_PORT           0x01#define ADDR_C_PORT           0x02#define C_PORT_LOW_IN_CMD     (0x01<<0)#define C_PORT_LOW_OUT_CMD    (~(0x01<<0))#define B_PORT_IN_CMD         (0x01<<1)#define B_PORT_OUT_CMD        (~(0x01<<1))#define C_PORT_UP_IN_CMD      (0x01<<3)#define C_PORT_UP_OUT_CMD     (~(0x01<<3))#define A_PORT_IN_CMD         (0x01<<4)#define A_PORT_OUT_CMD        (~(0x01<<4))#define _LE_L  (_LE = 0)#define _LE_H  (_LE = 1)#define _WR_L  (_WR = 0)#define _WR_H  (_WR = 1)#define _RD_L  (_RD = 0)#define _RD_H  (_RD = 1)#define _CS_L  (_CS = 0)#define _CS_H  (_CS = 1)sbit _LE = P2^7;sbit _WR = P2^5;sbit _RD = P2^6;sbit _CS = P2^4;uchar code DSY_CODE_Queue[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};uchar code DSY_Index[]={ 0x01,0x02,0x04,0x08,0x10,0x20,0x40,0x80};void WriteData8255(uchar addr, uchar dat);uchar ReadData8255(uchar addr);void Delay(uint x){ uchar i;while(x--){ for(i=0;i<120;i++);}}void WriteData8255(uchar addr, uchar dat){_CS_H;  _WR_H;  _RD_H;  _LE_H;  Delay(10);  _CS_L;  P0 = addr;  Delay(10);  _LE_L;    //锁存地址   P3 = dat;  Delay(10);  _WR_L;  Delay(10);  _WR_H;  Delay(10);  _CS = 1;}uchar ReadData8255(uchar addr){  uchar rval = 0;  _CS_H;_WR_H;_RD_H;_LE_H;Delay(10);_CS_L;P0 = addr;Delay(10);_LE_L;      //锁存地址_RD_L;      //启动读信号 P3 = 0xff;  //在置位后才能去读rval = P3;  Delay(10);_RD_H;Delay(10);_CS_H;  return rval;}void main(){uchar value = 0;uchar i,j,k;#if 1_CS = 1;_WR = 1;_RD = 1;//写控制字寄存器地址_LE = 1;Delay(10);_CS = 0;P0 = ADDR_CMD;  //A1A0=11，CS=0，写控制字Delay(10);_LE = 0;  //锁存器锁定地址P3 = 0x80; //PA,PB,PC全输出(方式选择)Delay(10);_WR = 0;Delay(10);_WR = 1;Delay(10);_CS = 1;#endif  WriteData8255(ADDR_CMD, 0x80); //配置8255工作在MOD0模式,PA,PB,PC全输出。 while(1){#if 1 for(k=0;k<8;k++){WriteData8255(ADDR_C_PORT, DSY_Index[k]);WriteData8255(ADDR_A_PORT, DSY_CODE_Queue[k]);///*写B端口数据，A1，A0 = 2'b01*///_CS = 1;//_WR = 1;//_RD = 1;////    _LE = 1;//Delay(10);//_CS = 0;//P0 = ADDR_C_PORT;  //Delay(10);//_LE = 0;//  P3 = DSY_Index[k];//  Delay(10); //_WR = 0;//Delay(10);//_WR = 1;//Delay(10);//_CS = 1;//Delay(10);//// /*写A端口数据，A1，A0 = 2'b00*///_CS = 1;//_WR = 1;//_RD = 1;////_LE = 1;//Delay(10);//_CS = 0;//P0 = ADDR_A_PORT;//Delay(10);//_LE = 0;//P3 = DSY_CODE_Queue[k]; //PA//Delay(10);//_WR = 0;//Delay(10);//_WR = 1;//Delay(10);//_CS = 1;Delay(200);}#endif//_CS = 1;//_WR = 1;//_RD = 1;////写控制字寄存器地址//_LE = 1;//Delay(10);//_CS = 0;//P0 = ADDR_CMD;  //A1A0=11，CS=0，写控制字//Delay(10);//_LE = 0;//P3 = 0x82; //PB输入,PA,PC输出(方式选择)//Delay(10);//_WR = 0;//Delay(10);//_WR = 1;//Delay(10);//_CS = 1; WriteData8255(ADDR_CMD, 0x82); //PB输入,PA,PC输出(方式选择)   // while(1);//  /*读B端口数据，A1，A0 = 2'b02*///  _CS = 1;//_WR = 1;//_RD = 1;//  //_LE = 1;//Delay(10);//_CS = 0;//P0 = ADDR_B_PORT;//Delay(10);//_LE = 0;//_RD = 0;//P3 = 0xff;  //在置位后才能去读//value = P3; //读取PB的值//Delay(10);//_RD = 1;//Delay(10);//_CS = 1;value = ReadData8255(ADDR_B_PORT);P1 = value; //将读取到的值赋值给P1Delay(200);while(1);}}