基于MSP430的I2C模拟总线程序讲解

程序和流程图IICHVOIDINIT_IICVOIDVOIDEEPROM_BYTEWRITEUNSIGNEDCHARNADDR,UNSIGNEDCHARNVALUNSIGNEDCHAREEPROM_RANDOMREADUNSIGNEDCHARNADDRUNSIGNEDCHAREEPROM_CURRENTADDRESSREADVOIDVOIDEEPROM_ACKPOLLINGVOIDVOIDINIT_CLKVOIDVOIDINIT_IIC_PORTVOIDMAINC/IICFORAT24C16ORAT24CXXX系列只要控制好IICRMIICSTPIICSTT其硬件会自动完成SCLSDA的一系列时序只要注意各个发送与接收的控制标志位/INCLUDEINCLUDE“IICH“VOLATILEUNSIGNEDCHARDATA6VOIDMAINVOID/VOLATILEUNSIGNEDCHARDATA6/停止看门狗WDTCTLWDTPWWDTHOLD/初始化端口INIT_IIC_PORT/初始化时钟INIT_CLK/I2C初始化INIT_IIC/置传输方式及控制方式/打开中断_EINT/写入数据EEPROM_BYTEWRITE0X0000,0X12/等待写操作完成EEPROM_ACKPOLLING/写入数据EEPROM_BYTEWRITE0X0001,0X34/等待写操作完成EEPROM_ACKPOLLING/写入数据EEPROM_BYTEWRITE0X0002,0X56/等待写操作完成EEPROM_ACKPOLLING/写入数据EEPROM_BYTEWRITE0X0003,0X78/等待写操作完成EEPROM_ACKPOLLING/写入数据EEPROM_BYTEWRITE0X0004,0X9A/等待写操作完成EEPROM_ACKPOLLING/写入数据EEPROM_BYTEWRITE0X0005,0XBC/等待写操作完成EEPROM_ACKPOLLING/读出数据，随机读DATA0EEPROM_RANDOMREAD0X0000/地址自动加1/读出数据，当前地址读DATA1EEPROM_CURRENTADDRESSREAD/读出数据，当前地址读DATA2EEPROM_CURRENTADDRESSREAD/读出数据，当前地址读DATA3EEPROM_CURRENTADDRESSREAD/读出数据，当前地址读DATA4EEPROM_CURRENTADDRESSREAD/读出数据，当前地址读DATA5EEPROM_CURRENTADDRESSREADIICCINCLUDEINCLUDE“IICH“DEFINESLAVEADDR0X50INTTX_COUNTINTRX_COUNTUNSIGNEDCHARI2CBUFFER3VOIDINIT_IICVOID/将P31和P33设置为I2C管脚P3SEL0X0A/设置P31和P33管脚的方向P3DIR/选择为I2C模式U0CTL|I2CSYNC/禁止I2C模块U0CTL/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I2CTCTLI2CTRXI2CSSEL_2/定义从器件地址I2CSASLAVEADDR/设置本身的地址I2COA0X01A5/I2C时钟为SMCLK/160I2CPSC159/SCL高电平为5I2C时钟I2CSCLH0X03/SCL低电平为5I2C时钟I2CSCLL0X03/I2C模块有效U0CTL|I2CENTX_COUNT0RX_COUNT0VOIDI2CWRITEINITVOID/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/清除中断标志I2CIFG/发送中断使能I2CIETXRDYIEVOIDI2CREADINITVOID/接收模式，R/W为1I2CTCTL/接收中断使能I2CIERXRDYIEVOIDEEPROM_BYTEWRITEUNSIGNEDCHARNADDR,UNSIGNEDCHARNVAL/等待I2C模块完成所有操作/在选定的地址写入数据WHILEI2CDCTL/设置地址数据I2CBUFFER1NADDR/设置数据I2CBUFFER0NVAL/设置缓冲区指针TX_COUNT1/写数据初始化I2CWRITEINIT/设置为主模式/发送数据的长度/1个控制字节，2个数据字节I2CNDAT2/开始和停止条件产生/开始I2C通信I2CTCTL|I2CSTTI2CSTPRETURNUNSIGNEDCHAREEPROM_CURRENTADDRESSREADVOID/等待I2C模块完成所有操作WHILEI2CDCTL/读操作的初始化I2CREADINIT/主MASTER模式U0CTL|MST/接收1个字节的数据I2CNDAT1/清除中断标志I2CIFG/开始接收，产生重新起始和停止条件I2CTCTL|I2CSTTI2CSTP/等待传输完成WHILEI2CIFG/返回数据RETURNI2CBUFFER0UNSIGNEDCHAREEPROM_RANDOMREADUNSIGNEDCHARNADDR/等待I2C模块完成所有操作WHILEI2CDCTL/设置地址I2CBUFFER0NADDR/设置缓冲区指针TX_COUNT0/写操作初始化I2CWRITEINIT/传输数据长度/1个控制字节和一个地址数据I2CNDAT1/清除中断标志I2CIFG/起始条件产生I2CTCTL|I2CSTT/等待传输完成WHILEI2CIFG/读操作初始化I2CREADINIT/接收一个字节的数据I2CNDAT1/清除中断标志I2CIFG/开始接收，产生重新起始和停止条件I2CTCTL|I2CSTTI2CSTP/等待传输完成WHILEI2CIFG/返回数据RETURNI2CBUFFER0VOIDEEPROM_ACKPOLLINGVOIDUNSIGNEDINTCOUNT/等待I2C模块完成所有操作WHILEI2CDCTLCOUNT0/清除I2CEN位U0CTLI2CTCTL|I2CRM/使能I2C模块U0CTL|I2CEN/设置NACKIFG标志I2CIFGNACKIFGWHILENACKIFG/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被清除WHILEI2CTCTL/产生停止条件I2CTCTL|I2CSTP/等待停止条件复位WHILEI2CDCTLCOUNTCOUNT1/清除I2CEN位U0CTLI2CTCTL/使能I2CU0CTL|I2CENRETURNIF_VER_0IWHILEIFG1/如果OSCFAULT1/OPENXT2,LFTX2选择低频率BCSCTL1/BCSCTL10X00功能一样/DCORSEL7FREQ3200K/25摄氏度）BCSCTL1|RSEL0RSEL1RSEL2BCSCTL1|0X07/MCLK的时钟源为TX2CLK，分频因子为1BCSCTL2SELM1/SMCLK的时钟源为TX2CLK，分频因子为1BCSCTL2SELS/对于系统时钟的选择关系到整个程序运行稳定性/文件名MSP430F169I2CC整体描述MSP430F169单片机硬件IIC软件,字节方式，主方式IIC接口P33SCL,P31SDA开漏输出相应寄存器地址寄存器I2COA用于存放自身从地址从方式时才有用地址寄存器I2CSA用于存放外围的从机地址主方式时才有用控制寄存器U0CTL硬件I2C的设置、使能、模式等。发送控制寄存器I2CTCTL数据控制寄存器I2CDCTL指示I2C总线的状态U0CTLRXDMAEN,TXDMAEN,I2C,XA,LISREN,SYNC,MST,I2CEN001001110X17I2CTCTLI2CWORD,I2CRM,I2CSSEL1,I2XSSEL0,I2CTRX,I2CSTB,I2CSTP,I2CSTT01100作者JY状态通过/INCLUDEINCLUDE“FPGACODEH“DEFINEWR24C512DEFINELED1_10X20/PORT35OUTPUTLED1/DEFINELED1_00XDFDEFINESDA_1P3OUT|BIT1/串行数据线，SDA1DEFINESDA_0P3OUT/DATAPOINTERELSESTATICINTNUMJ0/DATAPOINTERENDIFDEFINEI2CSLA0X50/功能描述检查总线是否空闲子程序状况0923调试通过/VOIDI2C_IDLE_CHECKVOIDWHILEI2CBUSY/I2CREADY在空闲状态0，空闲；1忙VOIDDELAYTIME10USUNSIGNEDCHARNUNSIGNEDCHARIWHILEN/5CYCLESFORI0I256字节模式，NEWSTART测试使用/选择方式I2CRM0，最终用户使用I2CTCTLI2CSSEL_2I2CNDAT2NDATNUM/最终用户使用，2BYTE地址128BYTE数据I2CPSC2/SETSCLI2CIFG0I2CSA0X50/SLAVEADDRESSOFAT24C512U0CTL|I2CEN/ENABLEI2CMODULE,7BITADDR,MASTERMODE0826U0CTL|MSTWHILEI2CBUSY/I2CREADY在空闲状态0，空闲；1忙I2CTCTL|I2CTRXI2CSTTI2CSTP/I2CRM0,启动总线,发送从器件地址WHILEI2CIFG/ACK为低电平，等待地址应答位,判断无应答NACKIFG1/子程标号I2CWRSLASUBADDR子程功能主机发送从机的子地址入口参数UNSIGNEDCHARSLA,UNSIGNEDINTSUBA参数说明子地址子程序状况0923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/UNSIGNEDCHARI2CSENDSUBADDRUNSIGNEDINTSUBA,UNSIGNEDCHARNDATNUMUNSIGNEDCHARHI_SUBA,LO_SUBAI2C_SENDNDATNUM/启动总线,等待地址应答位HI_SUBAUNSIGNEDCHARSUBA8LO_SUBAUNSIGNEDCHARSUBAI2CBUSSENDBYTEHI_SUBA/发送器件子地址WHILEI2CIFG/无应答，结束总线RETURN0I2CBUSSENDBYTELO_SUBA/发送器件子地址WHILEI2CIFG/无应答，结束总线RETURN0RETURN1/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UNSIGNEDCHARPS,UNSIGNEDCHARNUM参数说明写入数据的地址指针，数据个数子程序状况0923调试通过说明I2C读取数据/UNSIGNEDCHARI2CSENDSTRCONSTUNSIGNEDCHARPS,UNSIGNEDCHARNUM/UNSIGNEDCHARIUNSIGNEDCHARTEMPNUMTEMPNUMNUM1FORNUMI0NUMI8LO_SUBAUNSIGNEDCHARSUBAWHILEI2CBUSY/I2CREADY在空闲状态0，空闲；1忙I2CTCTL|I2CTRXI2CSTTI2CSTP/I2CRM0,启动总线,发送从器件地址WHILEI2CIFG/结束总线I2CBUSSENDBYTEHI_SUBA/发送器件子地址WHILEI2CIFG/结束总线I2CBUSSENDBYTELO_SUBA/发送器件子地址WHILEI2CIFG/结束总线DELAYTIME10US250DELAYTIME10US250DELAYTIME10US250DELAYTIME10US250/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况说明/VOIDINITI2CRECEUNSIGNEDCHARNUMP3OUT0X00/CLEARP3OUTPUTREGISTERP3SEL0X0A/P31SDA,P33SCL,SELECTI2CPINS,SETUPI2CMODULEU0CTL|I2CSYNC/SELECTI2CMODEXA0,7BIT_ADDRESINGU0CTL/I2C功能使能无效/I2CTCTLI2CRMI2CSSEL_2/I2CRM1XX256字节模式I2CTCTLI2CSSEL_2/I2CRM0I2CNDATNUM/1个字节I2CPSC1/SETSCL/I2CSCLH0X01/HIGHPERIODOFSCL/I2CSCLL0X01/LOWPERIODOFSCLI2CIFG0I2CSA0X50/SLAVEADDRESSOFAT24C512I2CTCTLU0CTL|I2CEN/ENABLEI2CMODULE,7BITADDR,MASTERMODE0826/功能描述读一个字节子程序状况/UNSIGNEDCHARI2CRECESLABYTEVOIDUNSIGNEDCHARCHDELAYTIME10US15U0CTL|MST/主模式WHILEI2CBUSY/I2CREADY在空闲状态0，空闲；1忙I2CTCTL|I2CSTTI2C