AT24C02是一款拥有256bytes(32Page)的EEPROM.

一 ：特点（部分）

1：双线接口；

2：双向数据传输协议；

3：400KHz波特率；

4：硬件写保护；

5：最大5ms写入同步；

6：100万次写操作；

7：100年数据存储。

 

基本框图

 

 

 

二：绝对参数

 

 

三：引脚定义

 

四：读写操作

AT24C02使用I2C进行读写操作，最大波特率为400KHz。

1：设备地址

设备地址由7bits组成，其中高4位默认为1010b,低三位由A0~A2控制。

2：写操作

1）单字节写

AT24C02单字节写，需要先写入设备地址，之后写入内存地址，最后写入数据。当IIC最后产生STOP模式后，AT24C02将会进入最大5ms的同步时间，此时无法对AT24C02进行操作。

写入时序如下：

 

 

 2）页写

AT24C02支持按页写操作，每页最大8个字节，一共32页。当进行按页写的时候，AT24C02内存地址会自动增加，如果地址已经是本页的最后地址，但是写操作还未完成，则地址会返回本页起始地址，数据将会覆盖。

 

 

 3：读操作

AT24C02支持当前地址读取，任意地址读取，连续读取。

1）当前地址读取

AT24C02在上电的时候，每次读写操作，都会自动同步地址。当使用IIC读取数据时，如果在写入设备地址时进行读操作，会读取当前同步地址的值。

 

 2）任意地址读取

AT24C02任意地址读取即为单字节读取。在写完设备地址，内存地址后，进行重起始操作，对数据进行读取。

 

 3）连续读取

AT24C02连续读取时，在读取第一个字节后，IIC不产生STOP条件，则AT24C02会继续传出数据，同时内存地址会自动更新，直到读取到设备的最大地址后，如果继续读取，则会读取设备内存的首地址值。

 

 五：代码参考（IIC 阻塞读写）–.c文件

  1 #include "at24c02.h"
  2 
  3 
  4 #define AT24C02_ADDR    (0xA0)
  5 
  6 
  7 uint8_t at24c02_write_buf[AT24C02_MAX_BYTE_NUM] = {0};
  8 uint8_t at24c02_read_buf[AT24C02_MAX_BYTE_NUM]  = {0};
  9 
 10 
 11 /**
 12   * @brief  AT24C02 write data.
 13   * @param  page, AT24C02 write page.
 14             data, Write data buffer.
 15   * @retval H_SUCCESS or H_ERROR.
 16   */
 17 H_STATUS_T Fn_AT24C02_WriteByte(uint8_t addr, uint8_t data)
 18 {
 19     uint8_t write_byte[1] = {data};
 20     HAL_StatusTypeDef status = HAL_OK;
 21 
 22     status = HAL_I2C_Mem_Write(&hi2c1, AT24C02_ADDR, addr, I2C_MEMADD_SIZE_8BIT, write_byte, 1, 0xFF);
 23 
 24     if(status != HAL_OK)
 25     {
 26         return H_ERROR;
 27     }
 28 
 29     return H_SUCCESS;
 30 }
 31 
 32 
 33 /**
 34   * @brief  AT24C02 write page data.
 35   * @param  page, AT24C02 write page.
 36             pData, Write data buffer.
 37             len, Write data length.
 38   * @retval H_SUCCESS or H_ERROR.
 39   */
 40 H_STATUS_T Fn_AT24C02_WritePage(H_AT24C02_PAGE_T page, uint8_t* pData, uint8_t len)
 41 {
 42     HAL_StatusTypeDef status = HAL_OK;
 43     uint8_t page_addr = (uint8_t)page;
 44 
 45     H_PARA_ASSERT((pData == NULL) || (len > AT24C02_PAGE_SIZE));
 46 
 47     status = HAL_I2C_Mem_Write(&hi2c1, AT24C02_ADDR, page_addr, I2C_MEMADD_SIZE_8BIT, pData, len, 0xFFFF);
 48 
 49     if(status != HAL_OK)
 50     {
 51         return H_ERROR;
 52     }
 53 
 54     return H_SUCCESS;
 55 }
 56 
 57 
 58 /**
 59   * @brief  AT24C02 write serial data.
 60   * @param  addr, AT24C02 write data memory.
 61             pData, Write data buffer.
 62             len, Write data length.
 63   * @retval H_SUCCESS or H_ERROR.
 64   */
 65 H_STATUS_T Fn_AT24C02_WriteData(uint8_t addr, uint8_t* pData, uint16_t len)
 66 {
 67     uint8_t start_page_remain = 0;
 68     uint8_t remain_page_num = 0;
 69     uint8_t write_num = 0;
 70     uint32_t i = 0;
 71 
 72     H_PARA_ASSERT(((AT24C02_MAX_BYTE_NUM - (addr + 1)) < len) || (pData == NULL));
 73 
 74     /* How many memory remain for start page */
 75     start_page_remain = AT24C02_PAGE_SIZE - addr % AT24C02_PAGE_SIZE;
 76 
 77     /* Write first page */
 78     write_num = len > start_page_remain ? start_page_remain : len;
 79     for(i = 0; i < write_num; i++)
 80     {
 81         if(H_SUCCESS != Fn_AT24C02_WriteByte(addr++, *pData++))
 82         {
 83             return H_ERROR;
 84         }
 85         len--;
 86 
 87         /* For auto sync write */
 88         Fn_DelayMs(5);
 89     }
 90 
 91     /* Write completely */
 92     if(len == 0)
 93     {
 94         return H_SUCCESS;
 95     }
 96 
 97     /* How many completely page to write */
 98     remain_page_num = len / AT24C02_PAGE_SIZE;
 99 
100     for(i = 0; i < remain_page_num; i++)
101     {
102         if(H_SUCCESS != Fn_AT24C02_WritePage((H_AT24C02_PAGE_T)addr, pData, AT24C02_PAGE_SIZE))
103         {
104             return H_ERROR;
105         }
106 
107         addr += AT24C02_PAGE_SIZE;
108         pData += AT24C02_PAGE_SIZE;
109         len -= AT24C02_PAGE_SIZE;
110 
111         /* For auto sync write */
112         Fn_DelayMs(5);
113     }
114 
115     /* Write cpm */
116     if(len == 0)
117     {
118         return H_SUCCESS;
119     }
120 
121     /* Last page remain number */
122     if(H_SUCCESS != Fn_AT24C02_WritePage((H_AT24C02_PAGE_T)addr, pData, len))
123     {
124         return H_ERROR;
125     }
126 
127     /* Note: if called Read function after this function, Please insert a delay time between write / read */
128     return H_SUCCESS;
129 }
130 
131 
132 /**
133   * @brief  AT24C02 read current address data.
134   * @param  pData, Read data buffer.
135   * @retval H_SUCCESS or H_ERROR.
136   */
137 H_STATUS_T Fn_AT24C02_ReadCurrentByte(uint8_t *pData)
138 {
139     H_PARA_ASSERT(pData == NULL);
140 
141     if(HAL_OK != HAL_I2C_Master_Receive(&hi2c1, AT24C02_ADDR, pData, 1, 0xFF))
142     {
143         return H_ERROR;
144     }
145 
146     return H_SUCCESS;
147 }
148 
149 
150 /**
151   * @brief  AT24C02 read a byte.
152   * @param  addr, AT24C02 read data memory.
153             pData, Read data buffer.
154   * @retval H_SUCCESS or H_ERROR.
155   */
156 H_STATUS_T Fn_AT24C02_ReadByte(uint8_t addr, uint8_t *pData)
157 {
158     H_PARA_ASSERT(pData == NULL);
159 
160     if(HAL_OK != HAL_I2C_Mem_Read(&hi2c1, AT24C02_ADDR, addr, I2C_MEMADD_SIZE_8BIT, pData, 1, 0xFF))
161     {
162         return H_ERROR;
163     }
164 
165     return H_SUCCESS;
166 }
167 
168 
169 /**
170   * @brief  AT24C02 read serial data.
171   * @param  addr, AT24C02 read data memory.
172             pData, Read data buffer.
173             len, Read data length.
174   * @retval H_SUCCESS or H_ERROR.
175   */
176 H_STATUS_T Fn_AT24C02_ReadData(uint8_t addr, uint8_t *pData, uint16_t len)
177 {
178     H_PARA_ASSERT((pData == NULL) || (len > AT24C02_MAX_BYTE_NUM));
179 
180     if(HAL_OK != HAL_I2C_Mem_Read(&hi2c1, AT24C02_ADDR, addr, I2C_MEMADD_SIZE_8BIT, pData, len, 0xFFFF))
181     {
182         return H_ERROR;
183     }
184 
185     return H_SUCCESS;
186 }
187 
188 
189 /**
190   * @brief  AT24C02 clear memory data.
191   * @param  None.
192   * @retval H_SUCCESS or H_ERROR.
193   */
194 H_STATUS_T Fn_AT24C02_ClearMemData(void)
195 {
196     uint32_t i = 0;
197     uint8_t  page_addr = 0x00;
198     uint8_t  data[AT24C02_PAGE_SIZE] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
199 
200     for(i = 0; i < AT24C02_PAGE_NUM; i++)
201     {
202         if(H_SUCCESS != Fn_AT24C02_WritePage((H_AT24C02_PAGE_T)page_addr, data, AT24C02_PAGE_SIZE))
203         {
204              return H_ERROR;
205         }
206 
207         page_addr += AT24C02_PAGE_SIZE;
208 
209         /* For auto sync write */
210         Fn_DelayMs(5);
211     }
212 
213     return H_SUCCESS;
214 }

 

 



六：代码参考：.h文件
  1 #ifndef __AT24C02_H__
  2 #define __AT24C02_H__
  3 
  4 
  5 #include "iic.h"
  6 
  7 #define AT24C02_BASE_ADDR           (0x00)
  8 
  9 #define AT24C02_PAGE_SIZE           (0x08)
 10 
 11 #define AT24C02_PAGE_NUM            (32)
 12 
 13 #define AT24C02_MAX_BYTE_NUM        (256)
 14 
 15 #define AT24C02_MAX_MEM_ADDR        (0xFF)
 16 
 17 typedef enum
 18 {
 19     AT24C02_PAGE0  = AT24C02_BASE_ADDR +  0 * AT24C02_PAGE_SIZE,
 20     AT24C02_PAGE1  = AT24C02_BASE_ADDR +  1 * AT24C02_PAGE_SIZE,
 21     AT24C02_PAGE2  = AT24C02_BASE_ADDR +  2 * AT24C02_PAGE_SIZE,
 22     AT24C02_PAGE3  = AT24C02_BASE_ADDR +  3 * AT24C02_PAGE_SIZE,
 23     AT24C02_PAGE4  = AT24C02_BASE_ADDR +  4 * AT24C02_PAGE_SIZE,
 24     AT24C02_PAGE5  = AT24C02_BASE_ADDR +  5 * AT24C02_PAGE_SIZE,
 25     AT24C02_PAGE6  = AT24C02_BASE_ADDR +  6 * AT24C02_PAGE_SIZE,
 26     AT24C02_PAGE7  = AT24C02_BASE_ADDR +  7 * AT24C02_PAGE_SIZE,
 27     AT24C02_PAGE8  = AT24C02_BASE_ADDR +  8 * AT24C02_PAGE_SIZE,
 28     AT24C02_PAGE9  = AT24C02_BASE_ADDR +  9 * AT24C02_PAGE_SIZE,
 29     AT24C02_PAGE10 = AT24C02_BASE_ADDR + 10 * AT24C02_PAGE_SIZE,
 30     AT24C02_PAGE11 = AT24C02_BASE_ADDR + 11 * AT24C02_PAGE_SIZE,
 31     AT24C02_PAGE12 = AT24C02_BASE_ADDR + 12 * AT24C02_PAGE_SIZE,
 32     AT24C02_PAGE13 = AT24C02_BASE_ADDR + 13 * AT24C02_PAGE_SIZE,
 33     AT24C02_PAGE14 = AT24C02_BASE_ADDR + 14 * AT24C02_PAGE_SIZE,
 34     AT24C02_PAGE15 = AT24C02_BASE_ADDR + 15 * AT24C02_PAGE_SIZE,
 35     AT24C02_PAGE16 = AT24C02_BASE_ADDR + 16 * AT24C02_PAGE_SIZE,
 36     AT24C02_PAGE17 = AT24C02_BASE_ADDR + 17 * AT24C02_PAGE_SIZE,
 37     AT24C02_PAGE18 = AT24C02_BASE_ADDR + 18 * AT24C02_PAGE_SIZE,
 38     AT24C02_PAGE19 = AT24C02_BASE_ADDR + 19 * AT24C02_PAGE_SIZE,
 39     AT24C02_PAGE20 = AT24C02_BASE_ADDR + 20 * AT24C02_PAGE_SIZE,
 40     AT24C02_PAGE21 = AT24C02_BASE_ADDR + 21 * AT24C02_PAGE_SIZE,
 41     AT24C02_PAGE22 = AT24C02_BASE_ADDR + 22 * AT24C02_PAGE_SIZE,
 42     AT24C02_PAGE23 = AT24C02_BASE_ADDR + 23 * AT24C02_PAGE_SIZE,
 43     AT24C02_PAGE24 = AT24C02_BASE_ADDR + 24 * AT24C02_PAGE_SIZE,
 44     AT24C02_PAGE25 = AT24C02_BASE_ADDR + 25 * AT24C02_PAGE_SIZE,
 45     AT24C02_PAGE26 = AT24C02_BASE_ADDR + 26 * AT24C02_PAGE_SIZE,
 46     AT24C02_PAGE27 = AT24C02_BASE_ADDR + 27 * AT24C02_PAGE_SIZE,
 47     AT24C02_PAGE28 = AT24C02_BASE_ADDR + 28 * AT24C02_PAGE_SIZE,
 48     AT24C02_PAGE29 = AT24C02_BASE_ADDR + 29 * AT24C02_PAGE_SIZE,
 49     AT24C02_PAGE30 = AT24C02_BASE_ADDR + 30 * AT24C02_PAGE_SIZE,
 50     AT24C02_PAGE31 = AT24C02_BASE_ADDR + 31 * AT24C02_PAGE_SIZE,
 51 }H_AT24C02_PAGE_T;
 52 
 53 
 54 
 55 /**
 56   * @brief  AT24C02 write data.
 57   * @param  page, AT24C02 write page.
 58             data, Write data buffer.
 59   * @retval H_SUCCESS or H_ERROR.
 60   */
 61 H_STATUS_T Fn_AT24C02_WriteByte(uint8_t addr, uint8_t data);
 62 
 63 
 64 /**
 65   * @brief  AT24C02 write page data.
 66   * @param  page, AT24C02 write page.
 67             pData, Write data buffer.
 68             len, Write data length.
 69   * @retval H_SUCCESS or H_ERROR.
 70   */
 71 H_STATUS_T Fn_AT24C02_WritePage(H_AT24C02_PAGE_T page, uint8_t* pData, uint8_t len);
 72 
 73 
 74 /**
 75   * @brief  AT24C02 write serial data.
 76   * @param  addr, AT24C02 write data memory.
 77             pData, Write data buffer.
 78             len, Write data length.
 79   * @retval H_SUCCESS or H_ERROR.
 80   */
 81 H_STATUS_T Fn_AT24C02_WriteData(uint8_t addr, uint8_t* pData, uint16_t len);
 82 
 83 
 84 /**
 85   * @brief  AT24C02 read current address data.
 86   * @param  pData, Read data buffer.
 87   * @retval H_SUCCESS or H_ERROR.
 88   */
 89 H_STATUS_T Fn_AT24C02_ReadCurrentByte(uint8_t *pData);
 90 
 91 
 92 /**
 93   * @brief  AT24C02 read a byte.
 94   * @param  addr, AT24C02 read data memory.
 95             pData, Read data buffer.
 96   * @retval H_SUCCESS or H_ERROR.
 97   */
 98 H_STATUS_T Fn_AT24C02_ReadByte(uint8_t addr, uint8_t *pData);
 99 
100 
101 /**
102   * @brief  AT24C02 read serial data.
103   * @param  addr, AT24C02 read data memory.
104             pData, Read data buffer.
105             len, Read data length.
106   * @retval H_SUCCESS or H_ERROR.
107   */
108 H_STATUS_T Fn_AT24C02_ReadData(uint8_t addr, uint8_t *pData, uint16_t len);
109 
110 
111 /**
112   * @brief  AT24C02 clear memory data.
113   * @param  None.
114   * @retval H_SUCCESS or H_ERROR.
115   */
116 H_STATUS_T Fn_AT24C02_ClearMemData(void);
117 
118 
119 extern uint8_t at24c02_write_buf[AT24C02_MAX_BYTE_NUM];
120 extern uint8_t at24c02_read_buf[AT24C02_MAX_BYTE_NUM];
121 
122 
123 #endif

 

 

原文地址：http://www.cnblogs.com/gigben/p/16818351.html

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