i2c.c

mtv512mg + mx88v462 液晶电视驱动C完整程序

/*-------------------------------------------------------------------------
I2C.C
Copyright 2004 Macronix International Co., Ltd.
-------------------------------------------------------------------------*/
#define _I2C_

#include "..\inc\public2.h"

#define	I2C_ACK		0
#define I2C_NACK	1

void 			I2C_SendStart(void);
void 			I2C_SendStop(void);
void 			I2C_SendACK(bit);
void 			I2C_SendByte(unsigned char );
unsigned char 	I2C_GetByte(bit);
	
//-------------------------------------------------------------------
//	I2C_ReleaseBus(void)
//-------------------------------------------------------------------
void I2C_Delay(unsigned char value)
{
	while(value>0) 
		value--;
}

//-------------------------------------------------------------------
//	I2C_SendStart(void)
//-------------------------------------------------------------------
void I2C_SendStart(void)
{
	I2C_SDA = 1;
	I2C_SCL = 1;
	I2C_Delay(2);
		
	I2C_SDA = 0;
	I2C_Delay(2);	
	I2C_SCL = 0;
}

//-------------------------------------------------------------------
//	I2C_SendStop(void)
//-------------------------------------------------------------------
void I2C_SendStop(void)
{
	I2C_SDA = 0;
	I2C_SCL = 1;		
	I2C_Delay(2);
	I2C_SDA = 1;		
	I2C_Delay(2);
}

//-------------------------------------------------------------------
//	I2C_SendByte(unsigned char val)
//-------------------------------------------------------------------
void I2C_SendByte(unsigned char val)
{
	unsigned char i;

    for (i=0; i<8; i++)
    {
    	I2C_SDA = (bit)(val & 0X80);
		I2C_SCL = 1;
		val <<= 1;
		I2C_Delay(1);
		I2C_SCL = 0;
    }

	I2C_SDA = 1;
	I2C_SCL = 1;
	I2C_Delay(1);
	I2C_SCL	= 0;
}

//-------------------------------------------------------------------
//	I2C_GetByte(bit ACK_NACK)
//			ACK  ->I2C_SDA = 0
//			NACK ->I2C_SDA = 1
//-------------------------------------------------------------------
unsigned char I2C_GetByte(bit ACK_NACK)
{
    unsigned char i;
    unsigned char rd_byte;

    rd_byte = 0;

    for(i=0; i<8; i++)
    {
		I2C_SCL = 1;
        rd_byte <<= 1;
		I2C_Delay(1);
		rd_byte |= I2C_SDA;
		I2C_SCL = 0;
    }

	I2C_SDA = ACK_NACK;
	I2C_SCL = 1;
	I2C_Delay(1);
	I2C_SCL = 0;
	I2C_SDA = 1;
	
    return(rd_byte);
}

/**--------------------------------------------------------------------------
* Name          void I2C_Write(unsigned char dev_addr, unsigned char start_addr,
*								unsigned char count , unsigned char *write_buf)
*
* Description	WRITE Control register BY I2C
*
* Flow Chart	1.Send Module Write ID address
*				2.Send Subaddress
*				3.Send Data(n byte)
*
* Return
*
* DATE          Author          Description
* ===========================================================================
**/
void I2C_Write(unsigned char dev_addr, unsigned char start_addr, unsigned char count , unsigned char *write_buf)
{
	unsigned char i;

    I2C_SendStart();
    I2C_SendByte(dev_addr);					//Write W_ID
    I2C_SendByte(start_addr);				//Write Address

	for(i=0;i<count;i++)
	{
    	I2C_SendByte(*(write_buf+i));		//Write multi-data
	}
   	I2C_SendStop();							//Stop
}

void I2C_WriteByte(unsigned char dev_addr, unsigned char start_addr, unsigned char write_byte)
{
    I2C_SendStart();
    I2C_SendByte(dev_addr);					//Write W_ID
    I2C_SendByte(start_addr);				//Write Address

    I2C_SendByte(write_byte);				//Write data
		
   	I2C_SendStop();							//Stop
}

/**--------------------------------------------------------------------------
* Name          void I2C_Read(unsigned char dev_addr, unsigned char start_addr,
*									unsigned char count, unsigned char *DATA_BUF )
*
* Description	READ Control register BY I2C
*
* Flow Chart	1.Send Module Write ID address
*				2.Send Subaddress
*				3.Send Module Read ID address
*				4.Read Data(n byte)
*
* Return
*
* DATE          Author          Description
* ===========================================================================
**/
void I2C_Read(unsigned char dev_addr, unsigned char start_addr, unsigned char count, unsigned char *DATA_BUF)
{
	unsigned char i;

    I2C_SendStart();
    I2C_SendByte(dev_addr);					//Write W_ID
	I2C_SendByte(start_addr);				//Write Address

    I2C_SendStart();
    I2C_SendByte(dev_addr|0X01);			//Write W_ID

	for(i=0;i<count-1;i++)
	{
		*(DATA_BUF+i)=I2C_GetByte(I2C_ACK);	//Read data from device(burst mode)
	}
	*(DATA_BUF+i) = I2C_GetByte(I2C_NACK);	//Read the last data then send NACK to STOP

	I2C_SendStop();							//Stop
}

unsigned char I2C_ReadByte(unsigned char dev_addr, unsigned char start_addr)
{
	unsigned char	rd_byte;

    I2C_SendStart();
    I2C_SendByte(dev_addr);					//Write W_ID
	I2C_SendByte(start_addr);				//Write Address

    I2C_SendStart();
    I2C_SendByte(dev_addr|0X01);			//Write W_ID

	rd_byte = I2C_GetByte(I2C_NACK);		//Read the last data then send NACK to STOP

	I2C_SendStop();							//Stop
   	
   	return(rd_byte);
}