MSP430FR5739实现模拟IIC

我使用的是MSP430Fr5739的芯片。下面直接放代码了。

#include "io430.h"
// P1.0 SCL
// P1.2 SDA
#define    SCL_HIGH    P1OUT|=BIT0
#define    SCL_LOW     P1OUT&=~BIT0
#define    SDA_HIGH    P1OUT|=BIT2
#define    SDA_LOW     P1OUT&=~BIT2
#define    SDA_OUT     P1DIR|=BIT2
#define    SDA_IN      P1DIR&=~BIT2
#define    SCL_OUT     P1DIR|=BIT0
#define    SDA         P1IN&BIT2



void IIC_start()
{
	SDA_OUT;
	SCL_OUT;
    SCL_HIGH;
    SDA_HIGH;
    __delay_cycles(10);
    SDA_LOW;
    __delay_cycles(10);
    SCL_LOW;
}

void IIC_stop()
{
	SDA_OUT;
	SCL_OUT;
    SCL_LOW;
    SDA_LOW;
    __delay_cycles(10);
    SCL_HIGH;
    __delay_cycles(10);
    SDA_HIGH;
    __delay_cycles(10);
}

void IIC_writebyte(unsigned char IIC_byte)
{
    unsigned char i;
	SDA_OUT;
	SCL_OUT;
	SCL_LOW;
	__delay_cycles(10);
    for(i=0;i<8;i++)  
    {
        if(IIC_byte&0x80)    //写1
            SDA_HIGH;
        else                 //写0
            SDA_LOW;
		__delay_cycles(10);
        SCL_HIGH;
	    __delay_cycles(10);
        SCL_LOW;
	    __delay_cycles(10);
        IIC_byte<<=1;         //循环左移，取最高位
    }
}

unsigned char IIC_readebyte()
{
    unsigned char i,k=0; 
	SDA_IN;       //SDA设置为输入
	SCL_OUT;
	SCL_LOW;
	__delay_cycles(50);
	for(i=0;i<8;i++)
	{
		SCL_HIGH;
		k=k<<1;
		if(SDA)
			k|=1;
        SCL_LOW;
        __delay_cycles(50);
	}
	SDA_OUT;        //SDA设置为输出
	__delay_cycles(50);
	return k;
}

unsigned char IIC_testACK()
{
	SCL_LOW;
	//SDA_IN;       //SDA设置为输入
	//SDA_UP;
	__delay_cycles(50);
	SCL_HIGH;
	__delay_cycles(50);
	SCL_LOW;
	//SDA_OUT;        //SDA设置为输出
	__delay_cycles(50);
	return 1;	
}

void IIC_masterACK()
{   
    SDA_OUT;
	SCL_OUT;
	SCL_LOW;
	SDA_LOW;
    SCL_HIGH;
	__delay_cycles(5);
	SCL_LOW;
	__delay_cycles(5);
}
	
void IIC_masterNACK()
{
	SDA_OUT;
	SCL_OUT;
	SCL_LOW;
	SDA_HIGH;
	__delay_cycles(5);
    SCL_HIGH;
	__delay_cycles(5);
	SCL_LOW;
	__delay_cycles(5);	
}