[参考译文] MSP430FR2433：软件 I2C

#include "include.h"



void Simulative_I2C_Init(void)
{
  P1DIR|= BIT2;
  P1DIR|= BIT3;
  PM5CTL0 &= ~LOCKLPM5;
  SCL_H;
  SDA_H;
  
}



void I2C_Start(void)
{
	SDA_H;
	SCL_H;
	delay_us(10);	
	SDA_L;
	delay_us(10);	
	SCL_L;			
	delay_us(10);		
}



void I2C_Stop(void)
{
	SDA_OUT;
	SDA_L;
	SCL_H;
	delay_us(10);	
	SDA_H;
	delay_us(10);	
	SCL_L;
}



void I2C_Ack(void)
{
	SDA_L;
	delay_us(10);		
	SCL_H;
	delay_us(10);	
	SCL_L;
	delay_us(10);		
}



void I2C_NoAck(void)
{
	SDA_H;
	delay_us(10);		
	SCL_H;
	delay_us(10);	
	SCL_L;
	delay_us(10);		
}



unsigned char Wait_Ack(void)
{
	unsigned char tiemout=0;
	
	SDA_H;
	delay_us(10);	
	SDA_IN;	   
	SCL_H;
	delay_us(10);		 
	while(READ_SDA)
	{
		tiemout++;
		if(tiemout>250)
		{
			I2C_Stop();
			return 1;
		}
	}
	SCL_L;
    SDA_OUT;	
	return 0;  
}



unsigned char Send_Byte(unsigned char l_u8Data)
{
	unsigned char i;
	for(i=0; i<8; i++)
	{
		SCL_L;
		delay_us(10);	
		if(l_u8Data & 0x80)
		{
			SDA_H;
		}
		else
		{
			SDA_L;
		}
		delay_us(10);	
		SCL_H;
		delay_us(10);	
		l_u8Data = l_u8Data << 1;
	}
	SCL_L;
	delay_us(10);	
	if(Wait_Ack())
	{
		return 1;
	}
  else
  {
    return 0;
  }
}



unsigned char Receive_Byte(void)
{
	unsigned char l_u8Count, l_u8RecData=0;
	SCL_L;
	delay_us(10);	
	SDA_H;
	SDA_IN;
	for(l_u8Count=0; l_u8Count<8; l_u8Count++)
	{
		SCL_H;
		delay_us(10);	
		l_u8RecData <<= 1;
		if(READ_SDA)
		{
			l_u8RecData |= 0x01;
		}
		SCL_L;
		delay_us(10);	
	}
	SDA_OUT;
	return l_u8RecData;
}



unsigned char I2C_WriteByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char l_u8Data)
{
	I2C_Start();
	
	if(Send_Byte(l_u8SlaveAddr&0xFE))
  {
    return 1;
  }

	if(Send_Byte(l_u8Addr))
  {
    return 1;
  }

	if(Send_Byte(l_u8Data))
  {
    return 1;
  }

	I2C_Stop();
  return 0;
}



unsigned char I2C_WriteNByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char* l_u8Data, unsigned char l_u8Length)
{
	unsigned char i;
	
	I2C_Start();
	
	if(Send_Byte(l_u8SlaveAddr&0xFE))
  {
    return 1;
  }

	if(Send_Byte(l_u8Addr))
  {
    return 1;
  }

	for(i=0; i<l_u8Length; i++)
	{
	  if(Send_Byte(l_u8Data[i]))
      {
        return 1;
      }
	}

  I2C_Stop();
  return 0;
}



unsigned char I2C_ReadByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char* l_u8Data)
{
	I2C_Start();
	
	if(Send_Byte(l_u8SlaveAddr&0xFE))
  {
    return 1;
  }

	if(Send_Byte(l_u8Addr))
  {
    return 1;
  }

	I2C_Start();
	
	if(Send_Byte(l_u8SlaveAddr|0x01))
  {
    return 1;
  }

	*l_u8Data = Receive_Byte();
	
	I2C_NoAck();

	I2C_Stop();	
	
	return 0;
}




unsigned char I2C_ReadNByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char* l_u8Data, unsigned char l_u8Length)
{
	unsigned char i;
	
	I2C_Start();
	
	if(Send_Byte(l_u8SlaveAddr&0xFE))
  {
    return 1;
  }

	if(Send_Byte(l_u8Addr))
  {
    return 1;
  }

	I2C_Start();
	
	if(Send_Byte(l_u8SlaveAddr|0x01))
  {
    return 1;
  }

	for(i=0; i<l_u8Length-1; i++)
	{
	  l_u8Data[i] = Receive_Byte();
		
		I2C_Ack();
	}
	l_u8Data[i] = Receive_Byte();
	
	I2C_NoAck();
	
	I2C_Stop();
  return 0;
}

#ifndef __SIMIIC_H
#define __SIMIIC_H

/******************************************IO宏定义******************************************/
#define SDA_IN 				(P1DIR &= ~ BIT2)
#define SDA_OUT 			(P1DIR |= BIT2)

#define READ_SDA   			P1IN & BIT2  

#define SDA_H 				(P1OUT |= BIT2) //p1.2 SDA
#define SDA_L 				(P1OUT &= ~BIT2)

#define SCL_H 				(P1OUT |= BIT3) // P1.3 SCL
#define SCL_L 				(P1OUT &= ~BIT3)

/******************************************函数接口声明******************************************/
extern void Simulative_I2C_Init(void);
extern void I2C_Start(void);
extern void I2C_Stop(void);
extern void I2C_Ack(void);
extern void I2C_NoAck(void);
extern unsigned char Wait_Ack(void);
extern unsigned char Send_Byte(unsigned char l_u8Data);
extern unsigned char Receive_Byte(void);
extern unsigned char I2C_WriteByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char l_u8Data);
extern unsigned char I2C_ReadByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char* l_u8Data);
extern unsigned char I2C_WriteNByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char* l_u8Data, unsigned char l_u8Length);
extern unsigned char I2C_ReadNByte(unsigned char l_u8SlaveAddr, unsigned char l_u8Addr, unsigned char* l_u8Data, unsigned char l_u8Length);
#endif