dstemp.c

一个通过打印机端口[378h]驱动lcd的程序. 并可通过ds1620测量温度,最后把结果在lcd中输出.

#include "lcdtemp.h"
#include "dstemp.h"

static int powerof2( int n )
{
	int i,res = 1;
	for( i = 1 ; i < n ; i++ )
		res *= 2;
	return res;
}

void DS_DQ_HIGH(void)
{
	LCD_RS_HIGH();
}


void DS_DQ_LOW(void)
{
	LCD_RS_LOW();
}

void DS_CLK_HIGH(void)
{
	unsigned char tmp = inb( PORTA + 2 );
	outb( 0xF7 & tmp , PORTA + 2 );
}

void DS_CLK_LOW(void)
{
	unsigned char tmp = inb( PORTA + 2 );
	outb( 0X08 | tmp , PORTA + 2 );
}

void DS_RST_HIGH(void)
{
	unsigned char tmp = inb( PORTA + 2 );
	outb( 0X04 | tmp , PORTA + 2 );
}

void DS_RST_LOW(void)
{
	unsigned char tmp = inb( PORTA + 2 );
	outb( 0XFB & tmp , PORTA + 2 );
}

void DS_WRITECMD(unsigned char cmd)
{
	DS_RST_HIGH();
	int i;
	for(i=0;i<8;i++)
	{
		DS_CLK_LOW();

		if( cmd & 0x01 )
			DS_DQ_HIGH();
		else
			DS_DQ_LOW();
		
		DS_CLK_HIGH();
		cmd >>=1 ;
	}
}

int DS_READ(void)
{
	DS_DQ_HIGH();
	int i,res,data = 0;
	for( i=0 ; i < 9 ; i++ )
	{
		DS_CLK_LOW();
		
		res = inb( PORTA + 1 );
		if( res & 0x40 )
			data = data + powerof2(i);
		DS_CLK_HIGH();		 
	}

	DS_RST_LOW();
	return data;
}