lcd._c

基于8515的lcd显示控制程序

//
//	File Name:		lcd.c
//
//	Title:			LCD interface implementation
//
//	Description:	Interface implementation file for the Hitachi HD44780U.
//					This driver is for the STK200.
//					STK200 port information
//					DATA = PORTA
//					RS	 = PORTC BIT 6
//					R/W	 = PORTD BIT 6
//					E	 = PORTC BIT 7
//
//	Creation Date:	2/2/00 11:49:37 PM
//
//	By:				A.C. Verbeck
//
//	This file is subject to the terms and conditions of the GNU General Public
//	License.  See the file COPYING in the main directory of this archive
//	for more details.
//

#include <io8515v.h>
#include <stdio.h>

#include "Basetype.h"
#include "t0.h"

#include "lcd.h"

//
//	Local defines
//
#define FUNCTION_SET		0x38					
#define CMD					0x00
#define DATA				0x01
#define	CMD_IO				(PUInt8)0x8000
#define	DATA_IO				(PUInt8)0xC000

//
//	Local data
//
static	UInt8	init_tab[] = {
	FUNCTION_SET,
	LCD_CLEAR,
	LCD_OFF,
	LCD_ON,
	LCD_CLEAR
};

//
//	Local functions
//
/*static void		LCD_write(UInt8 val, UInt8 sel);
static UInt8	LCD_read(UInt8 sel);
static void		LCD_busy_test(void);
static void		delay(UInt16 dly);*/

//
//	Function Name:
//		LCD_init
//
//	Description:
//		Initialize the LCD.
//
//	Parameters:
//		(none)
//
//	Returns:
//		(nothing)
//
void LCD_init(void)
{
	UInt8 i;

	for (i=0; i<5; i++) {
		LCD_busy_test();
		LCD_write(init_tab[i], CMD);
	}   
} 

//
//	Function Name:
//		LCD_clear
//
//	Description:
//		Clear the LCD.
//
//	Parameters:
//		(none)
//
//	Returns:
//		(nothing)
//
void LCD_clear(void)
{
	LCD_command(LCD_CLEAR);
}
                   
//
//	Function Name:
//		LCD_reset
//
//	Description:
//		Reset the LCD.
//
//	Parameters:
//		(none)
//
//	Returns:
//		(nothing)
//
void LCD_reset(void)
{
	T0_sleep(15);							//	Hitachi says wait 15mS before writing the LCD
	LCD_write(0x30, CMD);					//	Write the init (first time)
	T0_sleep(5);							//	Then, wait 4.1mS
	LCD_write(0x30, CMD);					//	Write the init again (second time)
	T0_sleep(1);							//	Then, wait 100uS
	LCD_write(0x30, CMD);					//	Write the init again (last time)
}

void LCD_command(UInt8 data)
{
	LCD_busy_test();
	LCD_write(data, CMD);
}

void LCD_putc(Char c)
{
	LCD_busy_test();
	if (c == '\n')
		LCD_command(LCD_NEW_LINE);
	else
		LCD_write(c, DATA);
}

void LCD_puts(String s)
{
	while (*s) {	
		LCD_busy_test();
		if (*s == '\n')
			LCD_command(LCD_NEW_LINE);
		else
			LCD_write(*s, DATA);
		++s;
	}
}


//
//	Function Name:
//		LCD_write
//
//	Description:
//		Write data or cmd to HD44780U
//
//	Parameters:
//		val	= data value to be written to HD44780U
//		sel	= data / cmd
//		0 - cmd write
//		1 - data write is selected
//
//	Returns:
//		(nothing)
//
static void LCD_write(UInt8 val, UInt8 sel)
{
	MCUCR = 0xC0;
	switch (sel) {
	case CMD:	*CMD_IO  = val;	break;
	case DATA:	*DATA_IO = val;	break;
	}
}
 
//
//	Function Name:
//		LCD_read
//
//	Description:
//		Read data or cmd to HD44780U
//
//	Parameters:
//		sel	= data / cmd
//		0 - cmd read
//		1 - data read
//
//	Returns:
//		data read from LCD
//
static UInt8 LCD_read(UInt8 sel)
{
	UInt8	rVal;
	MCUCR = 0xC0;
	switch (sel) {
	case CMD:	rVal = *CMD_IO;		break;
	case DATA:	rVal = *DATA_IO;	break;
	}
	return rVal;
}

//
//	Function Name:
//		LCD_busy_test
//
//	Description:
//		Test if the LCD is busy or not
//
//	Parameters:
//		(none)
//
//	Returns:
//		(nothing)
//
static void LCD_busy_test(void)
{
	while (LCD_read(CMD) & 0x80);
}