基于MSP430的I2C模拟总线程序讲解

1、程序和流程图IIC.hvoid Init_IIC(void);void EEPROM_ByteWrite(unsigned char nAddr,unsigned char nVal);unsigned char EEPROM_RandomRead(unsigned char nAddr);unsigned char EEPROM_CurrentAddressRead(void);void EEPROM_AckPolling(void);void Init_CLK(void);void Init_IIC_Port(void);Main.C1m*IIC for AT24c16OR AT24CXX

2、X 系歹 U只要限制好IICRM IICSTP IICSTT 其硬件会自动完成SCL SDA的一系列时序只要注意各个发送与接收的限制标志位*/#include <MSP430x16x.h>#include "IIC.h"volatile unsigned char Data6;void main(void)/volatile unsigned char Data6;/停止看门狗WDTCTL = WDTPW+WDTHOLD;初始化端口Init_IIC_Port();/初始化时钟Init_CLK();/I2C初始化Init_IIC();/置传输方式及限制方式翻开中断

3、_EINT();/写入数据EEPROM_ByteWrite(0x0000,0x12);/等待写操作完成EEPROM_AckPolling();/写入数据EEPROM_ByteWrite(0x0001,0x34);/等待写操作完成EEPROM_AckPolling();/写入数据EEPROM_ByteWrite(0x0002,0x56);/等待写操作完成EEPROM_AckPolling();/写入数据EEPROM_ByteWrite(0x0003,0x78);/等待写操作完成EEPROM_AckPolling();/写入数据EEPROM_ByteWrite(0x0004,0x9A);/等待写操

4、作完成EEPROM_AckPolling();/写入数据EEPROM_ByteWrite(0x0005,0xBC);/等待写操作完成EEPROM_AckPolling();读生数据,随机读Data0 = EEPROM_RandomRead(0x0000); / 地址自动力口 1读生数据,当前地址读Data1 = EEPROM_CurrentAddressRead();读生数据,当前地址读Data2 = EEPROM_CurrentAddressRead();读生数据,当前地址读Data3 = EEPROM_CurrentAddressRead();读生数据,当前地址读Data4 = EEPRO

5、M_CurrentAddressRead();读生数据,当前地址读Data5 = EEPROM_CurrentAddressRead();)IIC.C#include <MSP430x16x.h>#include "IIC.h"#define SLAVEADDR 0x50;int tx_count;int rx_count;unsigned char I2CBuffer3;void Init_IIC(void)/将P3.1和P3.3设置为I2C管脚P3SEL = 0x0A;设置P3.1和P3.3管脚的方向P3DIR &= 0x0A;选择为I2C模式U0C

6、TL |= I2C + SYNC;/禁止I2C模块U0CTL &=I2CEN;/设置I2C为7位地址模式,不使用 DMA ,字节模式,时钟源为 SMCLK,/设置成传输模式I2CTCTL = I2CTRX + I2CSSEL_2;/定义从器件地址I2CSA = SLAVEADDR;/设置本身的地址I2COA = 0X01A5;/I2C 时钟为 SMCLK / 160I2CPSC = 159;/SCL 高电平为：5 *I2C 时钟I2CSCLH = 0x03;/SCL低电平为：5 *I2C时钟I2CSCLL = 0x03;/I2C模块有效U0CTL |= I2CEN;tx_count =

7、 0;rx_count = 0;void I2CWriteInit(void)对于AT24CXXX的写操作是置成主模式并置位中断使能.主(Master)模式U0CTL |= MST;传输模式,R/W 为：0I2CTCTL |= I2CTRX;/去除中断标志I2CIFG &=TXRDYIFG;/发送中断使能I2CIE = TXRDYIE;)void I2CReadInit(void)(接收模式,R/W 为：1I2CTCTL &= I2CTRX;/接收中断使能I2CIE = RXRDYIE;)void EEPROM_ByteWrite(unsigned char nAddr, un

8、signed char nVal)(/等待I2C模块完成所有操作在选定的地址写入数据while (I2CDCTL&I2CBUSY);/设置地址数据I2CBuffer1 = nAddr;/设置数据I2CBuffer0 = nVal;/设置缓冲区指针tx_count = 1;/写数据初始化I2CWriteInit();/设置为主模式/发送数据的长度/1个限制字节,2个数据字节I2CNDAT = 2;/开始和停止条件产生/开始I2C通信I2CTCTL |= I2CSTT+I2CSTP;return;)unsigned char EEPROM_CurrentAddressRead(void)

9、(/等待I2C模块完成所有操作while (I2CDCTL&I2CBUSY);/读操作的初始化I2CReadInit();主(Master)模式U0CTL |= MST;/接收1个字节的数据I2CNDAT = 1;/去除中断标志I2CIFG &=ARDYIFG;开始接收,产生重新起始和停止条件I2CTCTL |= I2CSTT + I2CSTP;/等待传输完成while (I2CIFG)&ARDYIFG);/返回数据return I2CBuffer0;)unsigned char EEPROM_RandomRead(unsigned char nAddr) (/等待I2

10、C模块完成所有操作while (I2CDCTL&I2CBUSY);/设置地址I2CBuffer0 = nAddr;/设置缓冲区指针tx_count = 0;/写操作初始化I2CWriteInit();/传输数据长度/1个限制字节和一个地址数据I2CNDAT = 1;/去除中断标志I2CIFG &=ARDYIFG;/起始条件产生I2CTCTL |= I2CSTT;/等待传输完成while (I2CIFG)&ARDYIFG);/读操作初始化I2CReadInit();/接收一个字节的数据I2CNDAT = 1;/去除中断标志I2CIFG &= ARDYIFG;开始接

11、收,产生重新起始和停止条件I2CTCTL |= I2CSTT + I2CSTP;/等待传输完成while (I2CIFG)&ARDYIFG);/返回数据return I2CBuffer0;void EEPROM_AckPolling(void)unsigned int count;/等待I2C模块完成所有操作while (I2CDCTL&I2CBUSY);count=0;/去除I2CEN位U0CTL &= I2CEN;I2CTCTL |= I2CRM;/使能I2C模块U0CTL |= I2CEN;/设置NACKIFG标志I2CIFG = NACKIFG;while (N

12、ACKIFG & I2CIFG)/去除中断标志I2CIFG=0x00;/ 主(Master)模式U0CTL |= MST;/设置传输模式I2CTCTL |= I2CTRX;/产生起始条件I2CTCTL |= I2CSTT;/等待I2CSTT被去除while (I2CTCTL & I2CSTT);/产生停止条件I2CTCTL |= I2CSTP;/等待停止条件复位while (I2CDCTL & I2CBUSY);count = count + 1;/去除I2CEN位U0CTL &=I2CEN;I2CTCTL &=I2CRM;/使能I2CU0CTL |=

13、I2CEN;return;)#if VER < 200interrupt USART0TX_VECTOR void ISR_I2C(void)#else#pragma vector=USART0TX_VECTOR_interrupt void ISR_I2C(void)#endif/上面的程序其实只要编写：/#pragma vector=USART0TX_VECTOR_interruptvoid ISR_I2C(void)就行.switch (I2CIV)case I2CIV_AL:仲裁中断break;)case I2CIV_NACK:/NACK中断 break;case I2CIVOA

14、: /自己地址中断break;case I2CIV_ARDY:/访问准备好中断break;case I2CIV_RXRDY:/接收准备好中断I2CBuffer0=I2CDRB;break;case I2CIV_TXRDY:/发送准备好中断I2CDRB = I2CBuffertx_count;tx_count = tx_count - 1;if tx_count < 0/禁止发送中断I2CIE &=TXRDYIE;) break;)case I2CIV_GC:(一般调用中断 break;)case I2CIV_STT:(/起始条件中断 break;)void Init_IIC_Po

15、rt(void)(与IIC 口无关的PX 关闭以便于对编写系统初始化端口存放器板的综合程序/P1DIR = 0xFF;/P2DIR = 0xFF;P3DIR = 0xF5;/P4DIR = 0xFF;P5DIR = 0x7F;/P6DIR = 0xFF;/P4OUT = 0X11;/P5OUT &= 0XF0;P3SEL|=BIT1+BIT3;/在这里如果设置成)void Init_CLK(void)unsigned int i;/将存放器的容清零/XT2震荡器开启/LFTX1工作在低频模式/ACLK的分频因子为1BCSCTL1 = 0X00;do/去除OSCFault标志IFG1 &

16、amp;=OFIFG;for (i = 0x20; i > 0; i-);)while (IFG1 & OFIFG) = OFIFG); / 如果 OSCFault =1/open XT2, LFTX2选择低频率BCSCTL1 &= (XT2OFF + XTS); /BCSCTL1=0X00功能一样/DCO Rsel=7(Freq=3200k/25 摄氏度)BCSCTL1 |= RSEL0 + RSEL1 + RSEL2;BCSCTL1 |= 0x07;/MCLK的时钟源为TX2CLK,分频因子为 1BCSCTL2 += SELM1;/SMCLK的时钟源为TX2CLK,分

17、频因子为 1BCSCTL2 += SELS;)/对于系统时钟的选择关系到整个程序运行稳定性/* 文件名：msp430f169i2c.c* 整体描述：MSP430F169单片机硬件IIC软件,字节方式,主方式* IIC 接口： P3.3=SCL,P3.1=SDA;开漏输由* 相应存放器：地址存放器I2COA用于存放自身从地址从方 式时才有用地址存放器I2CSA用于存放外围的限制存放器U0CTL硬件I2C的设发送限制存放器I2CTCTL数据限制存放器I2CDCTL指示I2C*从机地址主方式时才有用*置、使能、模式等.*总线的状态U0CTL - RXDMAEN,TXDMAEN,I2C, XA,jy*

18、状态:通过LISREN,SYNC,MST,I2CEN(0x17)I2CTCTL -I2CWORD,I2CRM,I2CSSEL1,I2XSSEL0,I2CTRX,I2CSTB, I2CSTP, I2CSTT*作者:*/ #include <msp430x16x.h> #include "fpgacode.h"#define WR24C512#define LED11(0x20)/* Port 3.5 Output ->(0xdf)LED1 */ #define LED10/串#define SDA_1串行数据线,SDA = 1#define SDA_0BIT

19、1#define SCL_1行时钟线,SCL = 1P3OUT |= BIT1P3OUT &=/SDA = 0P3OUT |= BIT3#define SCL_0=0#define SDADIR_IN口为输入#define SDADIR_OUT 输由#define SDA_IN#define SCLDIR_IN输入#define SCLDIR_OUT 出#define SCL_IN#ifdef WR24C512static int numi = 0;#elsestatic int numj = 0;#endif#define I2CSLA 0x50P3OUT &= BIT3P3

20、DIR &= BIT1P3DIR |= BIT1(P3IN >> 1) & 0x01)P3DIR &= BIT3P3DIR |= BIT3/SCL/SDA,I/O/I/0 口 为/Read SDA/SCL,I/O 口为/I/0 口为输/Read SCL/Data Pointer/Data Pointer(P3IN >> 3) & 0x01)/*-功能描述：检查总线是否空闲-子程序状况：09-23调试通过-*/void I2c_Idle_Check(void)(while (I2CBUSY & I2CDCTL);/ I2C read

21、y?在空闲状态：0,空闲;1 :忙void DelayTime10us(unsigned char n)(unsigned char i;while(n-)/ 5 cyclesfor(i=0;i<10;i+);/ 8mhz 110:771 + 4 towhile/*-功能描述：发送数据：用于向总线发送数据-子程序状况：09-23调试通过-*/ void I2cBusSendByte(unsigned char c)while(I2CIFG & TXRDYIFG) != TXRDYIFG);I2CDRB = c;写发送存放器/检测发送准备/*MSP430 I2C写数据 09-23调

22、试通过*/*-功能描述：申请总线：进行I2C总线的初始化发送起始信号-子程序状况：09-23调试通过-*/void I2C_Send(unsigned char ndatNum) (清零,再次通讯必须重新置位P3OUT = 0x00;registerP3SEL = 0x0A;/注意:通讯结束,I2CMST自动/ clear P3 output/ P3.1=SDA,P3.3=SCL,Select I2C pins, Setup I2C moduleU0CTL |= (I2C + SYNC);mode;XA=0,7bit_addresing;U0CTL &= I2CEN;/ select

23、I2C/ i2c功能使能无效/ I2CTCTL = I2CRM + I2CSSEL_2;/ x(x>256)字节模式,new start最终用户使用,2byte地/ set scl/ Slave address of/ enable I2C module, 7/ I2C ready?/ I2CRM =0,启动总线,发/ ack为低电平,测试使用/选择方式I2CRM=0 ,最终用户使用I2CTCTL = I2CSSEL_2;I2CNDAT = 2 + ndatNum;/址+ 128byte 数据I2CPSC = 2;I2CIFG = 0;I2CSA = 0x50;At24c512U0CTL

24、 |= I2CEN; bit addr, master mode 08-26U0CTL |= MST;while (I2CBUSY & I2CDCTL);在空闲状态：0,空闲；1:忙I2CTCTL |= I2CTRX + I2CSTT + I2CSTP ;送从器件地址while(I2CIFG & NACKIFG) = 0x02);等待地址应答位,判断无应答NACKIFG = 1)/*- -子程标号:I2cWrSlaSubAddr- -子程功能：主机发送从机的子地址- -入口参数:unsigned char sla,unsigned intsuba- -参数说明：子地址- -子程

25、序状况：09-23调试通过- -说明：完成地址信息的定位,先确定顺序读写的起始地址-*/unsigned char I2cSendSubAddr(unsigned int suba,unsigned char ndatNum) /启动总线,等待地unsigned char Hi_suba,Lo_suba;I2C_Send(ndatNum);址应答位Hi_suba = ( unsigned char )( suba >> 8 );Lo_suba = ( unsigned char )( suba & 0x00ff );I2cBusSendByte( Hi_suba );whi

26、le(I2CIFG & 0x02) = NACKIFG )I2CTCTL |= I2CSTP;答,结束总线return(0);I2cBusSendByte( Lo_suba );址while(I2CIFG & 0x02 )=0x02 )/I2CTCTL |= I2CSTP;答,结束总线return(0);return(1);/发送器件子地址/等待数据的应答/无应/发送器件子地等待数据的应答/无应/*- -子程标号:I2cWriteStr(用户函数-子程功能:向I2C从器件写入数据- - 入口参数:unsigned char *ps,unsigned charnum- -参数说明

27、：写入数据的地址指针,数据个数- -子程序状况：09-23调试通过- -说明:I2C读取数据- -*/unsigned char I2cSendStr(const unsigned char * ps,unsigned char num) (/ unsigned char i;unsigned char tempnum;tempnum = num-1;for(numi=0;numi<tempnum;numi+)(/等待数据的I2cBusSendByte(*ps);while(I2CIFG & 0x02) = NACKIFG)应答(I2CTCTL |= I2CSTP;/无应答,结束

28、总线return(0);)ps+;)/ I2CTCTL |= I2CSTP; /I2CRM =1 模式中,在发送最后一个数据之前将停止位置位,*特别注意,必须I2cBusSendByte(*ps);while(I2CIFG & 0x02) = NACKIFG) / 等待数据的应答(I2CTCTL |= I2CSTP; /无应答,结束总线return(0);)return(1);)/ 写 at24c512-void I2cWrAt24c512(void)(unsigned int j=0;unsigned char m,n;unsigned int tempAddr;/ page wri

29、te/ I2Cfor (j = 0;j <462;j+) ( tempAddr = 128*j;while (I2CBUSY & I2CDCTL);ready?I2cSendSubAddr(tempAddr,0x80);I2cSendStr(FPGACfg+tempAddr,0x80);P4OUT A= 0x80;for (m=0;m<125;m+) for (n=0;n<110;n+);P4OUT a= 0x80;tempAddr = 128*j;while (I2CBUSY & I2CDCTL);/ I2C ready?I2cSendSubAddr(tem

30、pAddr,0x4f);I2cSendStr(FPGACfg+tempAddr,0x4f);P4OUT a= 0x80;for (m=0;m<125;m+) for (n=0;n<110;n+);P4OUT a= 0x80;/*MSP430 I2C读取数据*/*- -子程标号:I2cSlaSubAddr- -子程功能：主器件发送从机器件地址和子地址- -入口参数:unsigned intsuba- -参数说明：子地址- -子程调用:I2cBusSendByte- -子程序状况：Y- -说明：完成地址信息的定位,先确定顺序读写的起始地址-*/void I2cReceSubAddr(u

31、nsigned int suba)址unsigned char Hi_suba,Lo_suba;P3OUT = 0x00;registerP3SEL = 0x0A;P3.3=SCL,Select I2C pins, Setup I2C moduleU0CTL |= I2C + SYNC;mode;XA=0,7bit_addresing;U0CTL &=I2CEN;/ I2CTCTL = I2CRM + I2CSSEL_2;字节个数I2CTCTL = I2CSSEL_2;I2CNDAT = 2;址+ 128byte数据,固定字节I2CIFG = 0;I2CPSC = 1;/ I2CSCL

32、H = 0x02;/ I2CSCLL = 0x02;I2CSA = 0x50;/ test 09-25读之前先写地/ clear P3 output/ P3.1=SDA,/ select I2C/ i2c功能使能无效/ I2CRM = 1,自己设定/ I2CRM = 0,/ I2CRM = 0,2byte 地/ set scl/ High period of SCL/ Low period of SCL/ Slave address ofAt24c512U0CTL |= I2CEN;/ enable I2C module, 7bit addr,master mode08-26U0CTL |=

33、MST;Hi_suba = ( unsigned char )( suba >> 8 );Lo_suba = ( unsigned char )( suba & 0x00ff );while (I2CBUSY & I2CDCTL);/ I2C ready? 在空闲状态：0,空闲;1 :忙I2CTCTL |= I2CTRX + I2CSTT + I2CSTP ;/ I2CRM =0,启动总线,发送从器件地址while(I2CIFG & NACKIFG) = 0x02)/ ack 为低电平,等待地址应答位,判断 无应答NACKIFG = 1I2CTCTL |=

34、I2CSTP; / 结束总线I2cBusSendByte( Hi_suba );/ 发送器件子地址while(I2CIFG & NACKIFG) = 0x02)/ ack 为低电平,等待地址应答位,判断 无应答NACKIFG = 1I2CTCTL |= I2CSTP; / 结束总线I2cBusSendByte( Lo_suba );/ 发送器件子地址while(I2CIFG & NACKIFG) = 0x02)/ ack 为低电平,等待地址应答位,判断 无应答NACKIFG = 1I2CTCTL |= I2CSTP; / 结束总线DelayTime10us(250);DelayTime10us(250);DelayTime10us(250);DelayTime10us(250);/*- -子程标号：I2cSlaSubAddr- -子程功能：主器件接收初始化- -入口参数：无-子程序状-说明-*/void InitI2cRece(unsigned char num)(P3OUT = 0x00;register