lcd44780.c

本程序在S3C44B0 uClinux的嵌入式GUI

static void delay(int time)
{
	while(time --);
}

#define LCD_COMM_ADDR	0x0a000000
#define LCD_DATA_ADDR	0x0a000001

#ifndef outportb(port, data)
#define outportb(port, data)	*((volatile unsigned char *)(port)) = (unsigned char)(data)
#endif

/*********************************************************
	LCD44780(16chars * 1line)  initilization
*********************************************************/
void LCD44780_Init(void)
{
	//function set
	//data length = 8, line = 2, dots = 5x7
	outportb(LCD_COMM_ADDR, 0x38);
	delay(1000);
	
	//display On/Off control
	//display = ON, cursor = OFF, blinking = OFF
	outportb(LCD_COMM_ADDR, 0x0c);	
	delay(1000);
	
	//entry mode set
	//cursor moving direction = increment, shift/entire = entire
	outportb(LCD_COMM_ADDR, 0x06);
	delay(1000);
	
	//cursor or display shift
	//cursor moving / display shift = cursor moving, directiong = right
	outportb(LCD_COMM_ADDR, 0x1c);
	delay(1000);
	
	//clear display
	outportb(LCD_COMM_ADDR, 0x01);	//clear screen
	delay(100000);
	
	//return home
	outportb(LCD_COMM_ADDR, 0x02); //return home
	delay(100000);
}

/*********************************************************
	LCD44780(16chars * 1line)  display string
*********************************************************/
void LCD44780_Display(unsigned char * Asccode)
{
	int i;
	
	//clear display
	outportb(LCD_COMM_ADDR, 0x01);	//clear screen
	delay(100000);
	
	//return home	
	outportb(LCD_COMM_ADDR, 0x02);	//return home
	delay(100000);
	
	//display data
	i = 0;
	while(* Asccode != '\0'){
		if(i < 8){
			outportb(LCD_DATA_ADDR, *Asccode);	//data
			delay(1000);
		}
		else
			break;
			
		i ++;
		Asccode ++;
	}
	
	//set DD ram address, the second 8 chars start address = 0x40
	outportb(LCD_COMM_ADDR, 0xc0);
	delay(1000);
	
	while(* Asccode != '\0'){
		if(i < 16){
			outportb(LCD_DATA_ADDR, *Asccode);	//data
			delay(1000);
		}
		else
			break;
			
		i ++;
		Asccode ++;
	}
}