lcd.c

基于61A的时钟 LCD显示程序,非常的简洁,实用

/* 文件名：LCD.c */
/* LCD 控制器为HD44780U的1601液晶模块*/
#include "hardware.h"

#ifndef	__LCD_H__
#define	__LCD_H__
typedef struct bits  //定义可位操作的结构体
{
	unsigned int bit0:1;
	unsigned int bit1:1;
	unsigned int bit2:1;
	unsigned int bit3:1;
	unsigned int bit4:1;
	unsigned int bit5:1;
	unsigned int bit6:1;
	unsigned int bit7:1;
	unsigned int bit8:1;
	unsigned int bit9:1;
	unsigned int bit10:1;
	unsigned int bit11:1;
	unsigned int bit12:1;
	unsigned int bit13:1;
	unsigned int bit14:1;
	unsigned int bit15:1;
} BITS;
typedef union bit_word
{
	unsigned int word;
	BITS b;
} BIT_WORD;
#define BITSET(x, y) x.b.bit ## y = 1 //置位
#define BITCLR(x, y) x.b.bit ## y = 0 //清零
void Init_LCD(); // 初始化LCD
unsigned int ReadBF(); //读忙标志位
void LCD_Operate(unsigned char Operator, unsigned int Operand);//发数据或命令
void Toggle(); //E下降沿
void Display16CharString(unsigned char *str); //输出16个字符
#endif

/* 初始化LCD*/
void Init_LCD()
{ 
    LCD_Operate('C', 0x38);//单行显示 5*7点阵
    LCD_Operate('C', 0x01);//清LCD显示屏
    LCD_Operate('C', 0x06);//地址计数器递增，显示屏不移动
    LCD_Operate('C', 0x0c);//开显示，关光标，关闪烁   
    return;
}
//发数据或命令
void LCD_Operate(unsigned char Operator, unsigned int Operand)
{
	unsigned int x;
	BIT_WORD w;
	
	while(ReadBF());
	
	SP_Import(Port_IOB_Data, &x);
	w.word = x & 0xff00;
	switch(Operator)
	{
		case 'C':
		{
			   BITCLR(w, 13);//RS=0;
			   BITCLR(w, 14);//RW=0;			   
			   break;
		}
		case 'D':
		{
				BITSET(w, 13);//RS=1;
				BITCLR(w, 14);//RW=0;
				break;
		}
		default:
		       return;
	}
    Operand |= w.word;
    SP_Init_IOB(0xffff, 0x0000, 0xffff);
	SP_Export(Port_IOB_Data, Operand);
	
	Toggle();
	SP_Init_IOB(0xff00, 0x0000, 0xff00);						
	
	return;	
}
//读忙标志位
unsigned int ReadBF()
{	
	unsigned int x, LcdState;
	BIT_WORD w;
	
    SP_Import(Port_IOB_Data, &x);
	w.word = x & 0xff00;
	//RS=0;
	BITCLR(w, 13);
    //RW=1;
    BITSET(w, 14);
    SP_Export(Port_IOB_Data, w.word);
    //E=1;
    SP_Import(Port_IOB_Data, &x);
    w.word = x & 0xff00;;
    BITSET(w, 15);
    SP_Export(Port_IOB_Data, w.word);
    
	SP_Import(Port_IOB_Data, &LcdState);
	LcdState &= 0x0080;
    //E=0;
    SP_Import(Port_IOB_Data, &x);
    w.word = x & 0xff00;
    BITCLR(w, 15);
    SP_Export(Port_IOB_Data, w.word);    
	return LcdState;	
}
/* This function toggles the E line (LCD). */ 
void Toggle()
{          
    unsigned int x;
    BIT_WORD w;
    
    //E=1;
    SP_Import(Port_IOB_Data, &x);
    w.word = x;
    BITSET(w, 15);
    SP_Export(Port_IOB_Data, w.word);
    //E=0;   
    SP_Import(Port_IOB_Data, &x);
    w.word = x;
    BITCLR(w, 15);   
    SP_Export(Port_IOB_Data, w.word);
  
    return;
}
/* 显示16个字符*/
void Display16CharString(unsigned char *str)
{
   unsigned char position;
   int i;  

   position = 0;
   while (position<16)
   {
	    LCD_Operate('C', 0x80);
       	for(i=0;i<8;i++)
	    {
    	    LCD_Operate('D', str[position]);
		    position++;
		}
		LCD_Operate('C', 0xc0);
		for(i = 0; i < 8; i++)
		{
       		LCD_Operate('D', str[position]);
      		position++;
      	}            
    }	    
    return;  
}