i2c.c

T112 MCU源程码,用于T112外接MCU篇程,用来驱动模拟屏

#include "reg51.h"
#include "common.h"
#include "struct.h"
#include "system.h"
#include "twowire.h"

#define True 1
#define False 0
#define High  1
#define Low   0
//#define nop _nop()_

/*************************************************************************************************************************************************
									I2C总线驱动程序
**************************************************************************************************************************************************/



	void	Delay_10us(void)
	{
			twdDelay(5);			
	
	}
	
	/*************************************************/

	void	Start_I2C(void)
	{										
    	P_SCK	=	False	;
	  	Delay_10us()			;
		P_SDA	=	True	;
		Delay_10us()			;
		P_SCK	=	True	;
		Delay_10us()			;
		P_SDA	=	False	;				
		Delay_10us()			;
   		P_SCK	=	False	;
	}

	/***********************************************/

	void	Stop_I2C(void)
	{	
											
    		P_SCK	=	False;
		Delay_10us();
		P_SDA	=	False;
		Delay_10us();
    		P_SCK	=	True;
		Delay_10us();
		P_SDA	=	True;				
		Delay_10us();
    		P_SCK	=	False;
	}

	/***********************************************/

	void WByte_I2C(uCHAR  value)
	{
		uCHAR	i;
		for(i=0;i!=8;i++)
		{
			if( value&0x80 )
			{
				P_SDA	= True;
			}
			else
			{
				P_SDA	= False;
			}
			value	<<=1;
			Delay_10us();
    			P_SCK	=	True;
			Delay_10us();
    			P_SCK	=	False;
			Delay_10us();
		}
		P_SDA	= 	True;	
   		P_SCK	=	True;
		do
		{
			i++;
		}while(P_SDA&&i!=255);
   		P_SCK	=	False;
	}
	
	/**************************************************/
	
	uCHAR I2C_RByte(void)
	{
		uCHAR i;
		uCHAR RI2C_data=0;

		P_SDA	=	High;	
		for(i=0;i!=8;i++)
		{
    			P_SCK	=	High;
			Delay_10us();
			RI2C_data<<=1;
			if(P_SDA)
			{
				RI2C_data ++;
			}
    			P_SCK	=	Low;
			Delay_10us();
		}
		P_SDA	= 	High;
		Delay_10us();
   		P_SCK	=	High;
		Delay_10us();
   		P_SCK	=	Low;
		return RI2C_data;
	}
/*******************************************/

void  W_E2PROM(uCHAR slave_addr,uCHAR W_addr ,uCHAR W_data)
	{
		Start_I2C();
		WByte_I2C(slave_addr);
		WByte_I2C(W_addr);
		WByte_I2C(W_data);
		Delay_10us();
		///Wait_64us();
		Stop_I2C();
	}

/*************************************************/
uCHAR R_E2PROM(uCHAR slave_addr,uCHAR R_addr)
{
		uCHAR i;
		Start_I2C();
		WByte_I2C(slave_addr);
		WByte_I2C(R_addr);
		Start_I2C();
		WByte_I2C(slave_addr|0x01);
		i=I2C_RByte();
		Stop_I2C();
		return i;
}