AT24CXX系列程序

xiaoxiao2021-02-28 71

存储空间分配 AT24C02A，2K 串行 EEPROM：共 32 页，每页 8 字节，寻址字需 8 位。 AT24C04A，4K 串行 EEPROM：共 32 页，每页 16 字节，寻址字需 9 位。 AT24C08A，8K 串行 EEPROM：共 64 页，每页 16 字节，寻址字需 10 位。 AT24C16A，16K 串行 EEPROM：共 128 页，每页 16 字节，寻址字需 11 位。

图为几类不同容量的芯片的存储空间结构，24C16以下空间的大于8位后的寻址高位地址在片选地址中选择，详细看芯片手册。另外要注意的就是字节页，一次连续写入的数据量不能超过一页的数据量。有些老款的芯片甚至不支持跨页写入。为了适用也参照不跨页写入的方法写这个程序。而读取数据没有这个限制，只要单片机开辟的缓存够大，可以一直连续读下去。

/*****24Cxx Seriel EEPROM*************************/ #define EEPROM 8 /******** 01 -> 24C01; 02 -> 24C02; 04 -> 24C04; 08 -> 24C08; 16 -> 24C16; 32 -> 24C32; 64 -> 24C64; 128 -> 24C128; 256-> 24C256; 512 -> 24C512; *****/ #if EEPROM==1 #define PAGE_SIZE 8 #define EE_SIZE 0x007F #elif EEPROM==2 #define PAGE_SIZE 16 #define EE_SIZE 0x00FF #elif EEPROM==4 #define PAGE_SIZE 16 #define EE_SIZE 0x01FF #elif EEPROM==8 #define PAGE_SIZE 16 #define EE_SIZE 0x03FF #elif EEPROM==16 #define PAGE_SIZE 16 #define EE_SIZE 0x07FF #elif EEPROM==32 #define PAGE_SIZE 32 #define EE_SIZE 0x0FFF #elif EEPROM==64 #define PAGE_SIZE 32 #define EE_SIZE 0x1FFF #elif EEPROM==128 #define PAGE_SIZE 64 #define EE_SIZE 0x3FFF #elif EEPROM==256 #define PAGE_SIZE 64 #define EE_SIZE 0x7FFF #elif EEPROM==512 #define PAGE_SIZE 128 #define EE_SIZE 0xFFFF #endif 头文件可以写成预编译模式，方便移植后修改，PAGE_SIZE为一页的存储量，EE_SIZE为芯片的存储量，而后一些程序的判断也根据选择的存储芯片来判断。顶层用于外部程序调用的函数只有两个，读和写两个情况而已 unsigned　char　EEPROM_Write(unsigned　char*　pBuffer,unsigned　int　WriteAddress,unsigned char NumbyteToWrite); unsigned　char　EEPROM_Read(unsigned　char*　pBuffer,unsigned　int　ReadAddress,unsigned char NumbyteToWrite); 传递函数有三个： pBuffer:要存储或读出来的数据所在的变量存储区字符串头指针； WriteAddress/ReadAddress:要存入EEPROM所在的存储空间的第一个存储空间地址； NumbyteToWrite：数据写入或读出的字节个数；这样的应用比较简单例如在头文件中分配了两类数据的存储空间起始地址DATA1、DATA2 #define DATA1 0x0010 #define DATA2 0x0050 存储数据所在缓存 EE_Buffer[20]，应用程序如下写法： EEPROM_Write(EE_Buffer,DATA1,20); 这样EE_Buffer内的数据便被写入EEPROM中 0x10~0x30 的数据存储空间中了。合理的分配陪EEPROM 的存储空间对数据管理非常重要。甚至于可以作为一个小型黑匣子一样。 unsigned char EEPROM_Write(unsigned char* pBuffer,unsigned int WriteAddress,unsigned char NumbyteToWrite) { unsigned char TempBuffer,Temp2Buffer; if((WriteAddress+NumbyteToWrite) > EE_SIZE) //判断是否超出存储空间 { return 0; } else {// 连续写入两次避免因EMC等因素造成的写入失败情况 IIC_WriteBuffer(pBuffer,WriteAddress,NumbyteToWrite); IIC_WriteBuffer(pBuffer,WriteAddress,NumbyteToWrite); //读取eeprom 的数据与缓存中的数据对比相同为确认写入成功 IIC_ReadBuffer(&TempBuffer,WriteAddress+NumbyteToWrite-1,1); Temp2Buffer=*(pBuffer+NumbyteToWrite-1); if(TempBuffer==Temp2Buffer) return 1; else return 0; } } unsigned char EEPROM_Read(unsigned char* pBuffer,unsigned int ReadAddress,unsigned char NumbyteToWrite) { if((ReadAddress+NumbyteToWrite) > EE_SIZE) { return 0; } else { IIC_ReadBuffer(pBuffer,ReadAddress,NumbyteToWrite); IIC_ReadBuffer(pBuffer,ReadAddress,NumbyteToWrite); return 1; } } 接下来的是是IIC_ReadBuffer、IIC_WriteBuffer，两个函数主要是对存入数据的处理，如页面内写入，超过页面数量的数据处理等，我这里把函数定义为static 函数只能对内部应用，外部只能调用上面的两个函数，累似于API函数一样，这也可以避免不必要的程序调用书写。IIC_ReadBuffer函数相对简单，因为读取没有对页面的限制，可以无限制的读下去。读取缓存的函数只对地址做一下判断即可。写入函数较为复杂，需判断数据起始存储地址和页等关系 static void IIC_ReadBuffer(unsigned char* pBuffer,unsigned int ReadAddress,unsigned char NumbyteToWrite); static void IIC_WriteBuffer(unsigned char* pBuffer,unsigned int WriteAddress,unsigned char NumByteToWrite); void IIC_ReadBuffer(unsigned char* pBuffer,unsigned int ReadAddress,unsigned char NumbyteToWrite) { u8 PageAddress=0; /******pageAddress is over 8bit***********/ /******判断存储地址是否超过8位************/ #if EEPROM < 32 PageAddress=(u8)(ReadAddress>>7)&0x0E|ReadAddress_EEPROM; #else PageAddress=WriteAddress_EEPROM; #endif IIC_ReadPage(pBuffer,PageAddress,ReadAddress,NumbyteToWrite); } void IIC_WriteBuffer(unsigned char* pBuffer,unsigned int WriteAddress,unsigned char NumByteToWrite) { u8 NumOfPage=0,NumOfSingle=0; // u16 Part=0;// u8 PageAddress=0; /******pageAddress is over 8bit***********/ /******判断存储地址是否超过8位************/ #if EEPROM < 32 PageAddress=(u8)(WriteAddress>>7)&0x0E|WriteAddress_EEPROM; #else PageAddress=WriteAddress_EEPROM; #endif /*********判断起始地址与跨页地址的字节个数********/ Part=WriteAddress/PAGE_SIZE; if(Part!=0) { Part=PAGE_SIZE*(Part+1)-WriteAddress; } else { Part=PAGE_SIZE-WriteAddress; } /******/ if(Part >= NumByteToWrite) { /***写入的数据个数小于跨页剩余的个数可直接写入 ***/ IIC_WritePage(pBuffer,PageAddress,WriteAddress,NumByteToWrite); } else { NumOfPage = (NumByteToWrite-Part)/PAGE_SIZE; NumOfSingle = (NumByteToWrite-Part)%PAGE_SIZE; pBuffer = IIC_WritePage(pBuffer,PageAddress,WriteAddress,Part); /***1.写入的数据个数大于跨页剩余的个数先把剩余的跨页个数填充满 ***/ NumByteToWrite -= Part; WriteAddress += Part; while(NumOfPage--) { pBuffer = IIC_WritePage(pBuffer,PageAddress,WriteAddress,PAGE_SIZE); /***2.按计算的数据量占页面数，连续写入页面*******/ WriteAddress += PAGE_SIZE; } if(NumOfSingle!=0) { IIC_WritePage(pBuffer,PageAddress,WriteAddress,NumOfSingle); /***3.补充页面写完后超出的不足一页数据量的数据***/ } } } 剩下的是IIC_WritePage()、IIC_ReadPage()两个函数是芯片的IIC通讯底层函数，根据单片机的IIC通讯模式写入即可。以上的程序可通用到任何24Cxx 系列所应用的程序。

在实际应用中要注意的便是存储空间的分配，已经空间长度的输入，这样EEPROM的使用便能得心应手

void I2C_EE_Init() { /* depending on the EEPROM Address selected in the i2c_ee.h file */ #ifdef EEPROM_Block0_ADDRESS /* Select the EEPROM Block0 to write on */ EEPROM_ADDRESS = EEPROM_Block0_ADDRESS; #endif #ifdef EEPROM_Block1_ADDRESS /* Select the EEPROM Block1 to write on */ EEPROM_ADDRESS = EEPROM_Block1_ADDRESS; #endif #ifdef EEPROM_Block2_ADDRESS /* Select the EEPROM Block2 to write on */ EEPROM_ADDRESS = EEPROM_Block2_ADDRESS; #endif #ifdef EEPROM_Block3_ADDRESS /* Select the EEPROM Block3 to write on */ EEPROM_ADDRESS = EEPROM_Block3_ADDRESS; #endif } void I2C_ByteWrite(u8* pBuffer, u8 WriteAddr)//Ð´Ò»¸ö×Ö½Ú { I2C_GenerateSTART(I2C1, ENABLE); //ÆðÊ¼ÐÅºÅ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));//Çå³ýEV5 I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//·¢ËÍ´ÓÆ÷¼þµØÖ· while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//Çå³ýEV6 I2C_SendData(I2C1, WriteAddr);//Ð´µÄµØÖ·00~FF while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//EV8-1 I2C_SendData(I2C1, *pBuffer); //·¢ËÍÊý¾Ý while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//Çå³ýEv8 I2C_GenerateSTOP(I2C1, ENABLE);//²úÉúÍ£Ö¹ÐÅºÅ } void I2C_PageWrite(u8* pBuffer, u8 WriteAddr, u8 NumByteToWrite)//Á¬ÐøÐ´¶à¸ö×Ö½Ú { while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY)); // ÅÐ¶Ï×ÜÏßÊÇ·ñ·±Ã¦ I2C_GenerateSTART(I2C1, ENABLE); while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));//EV5 I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//·¢ËÍ´ÓÆ÷¼þµØÖ· while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//Çå³ýEV6 I2C_SendData(I2C1, WriteAddr);//Ð´µÄµØÖ·00~FF while(! I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//EV8-1 while(NumByteToWrite--) { I2C_SendData(I2C1, *pBuffer); pBuffer++; while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//Çå³ýEv8 } I2C_GenerateSTOP(I2C1, ENABLE);//²úÉúÍ£Ö¹ÐÅºÅ } void I2C_WaitEepromStandbyState(void)//µÈ´ý²Ù×÷Íê³É { vu16 SR1_Tmp = 0; do { I2C_GenerateSTART(I2C1, ENABLE);//ÆðÊ¼ÐÅºÅ SR1_Tmp = I2C_ReadRegister(I2C1, I2C_Register_SR1);//¶ÁÈ¡¼Ä´æÆ÷±êÖ¾Î» I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter); } while(!(I2C_ReadRegister(I2C1, I2C_Register_SR1) & 0x0002)); I2C_ClearFlag(I2C1, I2C_FLAG_AF);//Çå³ý I2C_GenerateSTOP(I2C1, ENABLE); } void I2C_BufferWrite(u8* pBuffer, u8 WriteAddr, u16 NumByteToWrite)//ºÍ25X16Ò»Ñù { u8 NumOfPage = 0; u8 NumOfSingle = 0; u8 Addr = 0; u8 count = 0; Addr = WriteAddr % I2C_PageSize;//¿´¿´²»ÂúÒ»Ò³µÄÓÃÁË¶àÉÙ count =I2C_PageSize-Addr;//²»ÂúÒ»Ò³Ã»ÓÃµÄ²¿·Ö NumOfPage = NumByteToWrite / I2C_PageSize;//Ò»¸ö¶àÉÙÒ³ NumOfSingle = NumByteToWrite % I2C_PageSize;//²»ÂúÒ»Ò³×Ö½ÚÊý if(Addr == 0)//Ò³Í·¿ªÊ¼Ð´ { if(NumOfPage == 0)//²»ÂúÒ»Ò³ { I2C_PageWrite(pBuffer, WriteAddr, NumOfSingle); I2C_WaitEepromStandbyState(); } else//³¬¹ýÒ»Ò³ { while(NumOfPage--)//ÕûÒ³Ð´ { I2C_PageWrite(pBuffer, WriteAddr,I2C_PageSize); I2C_WaitEepromStandbyState(); WriteAddr += I2C_PageSize; pBuffer += I2C_PageSize; } if(NumOfSingle!=0)//²»ÂúÕûÒ³µÄ { I2C_PageWrite(pBuffer, WriteAddr, NumOfSingle); I2C_WaitEepromStandbyState(); } } } else//ÆðÊ¼µØÖ·²»ÊÇÒ³Í· { if(NumOfPage== 0) { I2C_PageWrite(pBuffer, WriteAddr, NumOfSingle); I2C_WaitEepromStandbyState(); } else { NumByteToWrite -= count; NumOfPage = NumByteToWrite / I2C_PageSize; NumOfSingle = NumByteToWrite % I2C_PageSize; if(count != 0) { I2C_PageWrite(pBuffer, WriteAddr, count); I2C_WaitEepromStandbyState( ); WriteAddr += count; pBuffer += count; } while(NumOfPage--) { I2C_PageWrite(pBuffer, WriteAddr, I2C_PageSize); I2C_WaitEepromStandbyState(); WriteAddr += I2C_PageSize; pBuffer += I2C_PageSize; } if(NumOfSingle != 0) { I2C_PageWrite(pBuffer, WriteAddr, NumOfSingle); I2C_WaitEepromStandbyState(); } } } }

void I2C1_GPIO_Config() { GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD; GPIO_Init(GPIOB, &GPIO_InitStructure); } void I2C1_Config() { I2C_InitTypeDef I2C_InitStructure; I2C_DeInit(I2C1); I2C_InitStructure.I2C_Mode = I2C_Mode_I2C; I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2; I2C_InitStructure.I2C_OwnAddress1 =0XA0; I2C_InitStructure.I2C_Ack = I2C_Ack_Enable; I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; I2C_InitStructure.I2C_ClockSpeed = 400000; I2C_Init(I2C1, &I2C_InitStructure);// I2C_Cmd(I2C1, ENABLE);//´ò¿ªI2C1 I2C_AcknowledgeConfig(I2C1, ENABLE);//ÔÊÐíÓ¦´ð }

void I2C_BufferRead(u8* pBuffer, u8 ReadAddr, u16 NumByteToRead)//¶ÁÒ»´®Êý { while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));// ÅÐ¶Ï×ÜÏßÊÇ·ñ·±Ã¦ I2C_GenerateSTART(I2C1, ENABLE); //ÆðÊ¼ÐÅºÅ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));//EV5 I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//·¢ËÍ´ÓÆ÷¼þµØÖ· while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//Çå³ýEV6 I2C_Cmd(I2C1, ENABLE); I2C_SendData(I2C1, ReadAddr);//Òª¶ÁÊý¾ÝµÄµØÖ· while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//EV8-1 I2C_GenerateSTART(I2C1, ENABLE);//ÆðÊ¼ÐÅºÅ while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));//Çå³ýEV5 I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Receiver);//¸æËßÆ÷¼þ ÎÒÒª¶ÁÊý¾Ý while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));//EV6 while(NumByteToRead) { if(NumByteToRead == 1)//Ê£×îºóÒ»¸öÊý¾ÝÊ± { I2C_AcknowledgeConfig(I2C1, DISABLE);//¹Ø±ÕÓ¦´ð I2C_GenerateSTOP(I2C1, ENABLE);// Ê¹ÄÜÍ£Ö¹ } if(I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED))//EV7 ÓÐ½ÓÊÕÊ± { *pBuffer = I2C_ReceiveData(I2C1);//µôÓÃ¿âº¯Êý pBuffer++; // NumByteToRead--;// } } I2C_AcknowledgeConfig(I2C1, ENABLE);//´ò¿ªÓ¦´ð ÎªÏÂÒ»´Î×¼±¸ }

1. 注意24C16的管脚7是写保护,需要把它拉低

2.如果没有级联。最好A2 A1 A0 最好都接地

2. 24C16只能挂1个

3. 24C16的A2,A1,A0都是扇区地址

I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);

EEPROM_ADDRESS就是八个扇区代表 0XA0 0XA2 0XA4 0XA6 0XA8 0XAA 0XAC 0XAE

Send7bit意思是前7位自己决定最后一位方向为由I2C_Direction_Transmitter决定，看源码就知道了

I2C_SendData(I2C1, WriteAddr1);决定每个扇区内256个字节的具体地址

4 24C16有8个扇区（block） 128个页 2048字节 16k位

1扇区有16页 1页有16字节

4. 24C16的IIC函数第二个地址是从0开始,每256byte进行加一次地址,也就是说每次读写最大就是256byte,超过了的,要重新写地址,第二次地址= 0+256开始,继续最大写256byte ,第三次地址是0+256+256这样循环下去写好像24C16有自动地址溢出的功能

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