MSP430单片机硬件IIC

//MSP430IIC接口是很方便的物件，但是还是有很多人弃之不用，当然有各种原因，但是如果你确实要用IIC接口，而且容许的话，用它还是很舒服的，可能开始不太顺，但是一旦搞通了你会体会到他的好处。
我看了一些网上的程序，有的仍然用模拟方式的思维处理某些环节，比如应答信号。非要追踪”ACK”不可，其实接口已经提供了“NACK”中断，何必非要反向处理呢？事实上，如果在正常传送中出现“NACK”中断，你要考虑更换器件或者考虑系统的稳定性了。

#include <msp430x16x.h>
unsigned char RX_BUF[10];
unsigned char TX_BUF[16];
unsigned char Rece_data[16];

int RX_COUNTER;
int TX_COUNTER;

void Init_IIC(void);
void EEPROM_WriteN(unsigned char mAddr,unsigned char sAddr,unsigned char n);
unsigned char EEPROM_ByteRead(unsigned char mAddr,unsigned char sAddr);
void EEPROM_ReadN(unsigned char mAddr,unsigned char sAddr,unsigned char n);
//=======================================
//USART0中断
//=======================================
#pragma vector = USART0TX_VECTOR
__interruptvoid I2C_ISR(void)
{
switch(I2CIV)
{
case 2: I2CTCTL |= I2CSTP; I2CIFG=0; break;//无应答
case 10: RX_BUF[RX_COUNTER] = I2CDRB;
RX_COUNTER++;
break;

case 12: I2CDRB = TX_BUF[TX_COUNTER];
TX_COUNTER++;
break;
default: break;
}
}

//====================================
//系统时钟初始化
//====================================
void INIT_SYSTIMER(void)
{
unsigned char i;
BCSCTL1 &= ~XT2OFF;//选 XT2
do
{
IFG1 &= ~OFIFG;//清除震荡器失效标志
for (i = 0xFF; i > 0; i--);//稳定时间
}
while ((IFG1 & OFIFG)!=0);//如果震荡器失效标志存在，等待
BCSCTL2 = SELM_2 + SELS + DIVS_3;//MCLK时钟源=XT2，SMCLK时钟源=XT2/8
}
//=================================
void delay(unsigned int i)
{
unsigned int j;
for(j=0;j }

//=================================================
void Init_IIC(void)
{
P3SEL |= 0x0a;
U0CTL = I2C + SYNC;
U0CTL &= ~I2CEN;
I2CTCTL |= I2CSSEL_2;//SMCLK
I2CPSC = 9;//I2C时钟 = SMCLK / 10: 100KH;
I2CSCLH = 0x03;//SCL 高电平为：5 *I2C 时钟
I2CSCLL = 0x03;//SCL 低电平为：5 *I2C 时钟
I2CSA = 0X50;
I2CNDAT = 0x02;
U0CTL |= I2CEN;//I2C 模块有效
I2CIE |= TXRDYIE + RXRDYIE; //Enable TX RX interrupt
}
//=================================================
//对于FM24L16的写操作发送N个数据
//16>n>0
//0x50<=mAddr<=0x57sAddr<16;
//=================================================
void EEPROM_WriteN(unsigned char mAddr,unsigned char sAddr,unsigned char n)
{
I2CSA = mAddr;//页地址
TX_BUF[0] = sAddr;//子地址
I2CNDAT = n;//计数器初值
TX_COUNTER = 0;
while (I2CDCTL & I2CBUSY);//检查模块忙
I2CIFG =0;//中断标志清零
I2CIE |= TXRDYIE;
U0CTL |= MST;
I2CTCTL |= I2CTRX + I2CSTT + I2CSTP;
while ((~I2CIFG) & ARDYIFG); //检查发送结束
}
//===================================================
//读1个字节
//===================================================
unsigned char EEPROM_ByteRead(unsigned char mAddr,unsigned char sAddr)
{
I2CSA = mAddr;//页地址
TX_BUF[0] = sAddr;//子地址
TX_COUNTER = 0;//计数器初值
RX_COUNTER = 0;

while (I2CDCTL & I2CBUSY);//检查模块忙
I2CNDAT = 1;//1位数据=子地址
I2CIFG = 0;//中断标志清零
I2CIE |= TXRDYIE;
U0CTL |= MST;
I2CTCTL |= I2CTRX + I2CSTT;//置位起始位发送子地址
while ((~I2CIFG) & ARDYIFG);//检查发送结束

I2CIFG &= ~ARDYIFG;
I2CIE |= RXRDYIE;
I2CTCTL &= ~I2CTRX;
I2CTCTL |= I2CSTT + I2CSTP;//接收1位数据后置位停止位
while ((~I2CIFG) & ARDYIFG);//检查接收结束

return RX_BUF[0];//返回接收的1字节数据
}
//======================================
//n=读N个字节，mAddr页地址；sAddr子地址
//======================================
void EEPROM_ReadN(unsigned char mAddr,unsigned char sAddr,unsigned char n)
{
unsigned char i;
unsigned char k;
unsigned char m=0;
k = sAddr + n;
for(i=sAddr;i {
Rece_data[m]=EEPROM_ByteRead(mAddr,i);
m++;
}
}



//==================================
void SAVE_DATA(unsigned char mAddr,unsigned char sAddr,unsigned char n)
{
TX_BUF[1] = 0X41;
TX_BUF[2] = 0X42;
TX_BUF[3] = 0X43;
TX_BUF[4] = 0X44;
TX_BUF[5] = 0X45;
TX_BUF[6] = 0X46;
TX_BUF[7] = 0X47;
TX_BUF[8] = 0X48;
TX_BUF[9] = 0X49;
TX_BUF[10] = 0X4A;
TX_BUF[11] = 0X4B;

EEPROM_WriteN(0x50,0x00,n+1);
}

//==================================
int main(void)
{
WDTCTL = WDTPW + WDTHOLD;// Stop WDT
INIT_SYSTIMER();
Init_IIC();
_EINT();//打开中断

while(1)
{
//=================================

SAVE_DATA(0x50,0x00,11);
EEPROM_ReadN(0x50,0x00,11);

delay(10);
//=================================
}