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[256] = {0};
8 uint8_t at24c02_read_buf[256] = {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 return H_SUCCESS; 128 } 129 130 131 /** 132 * @brief AT24C02 read current address data. 133 * @param pData, Read data buffer. 134 * @retval H_SUCCESS or H_ERROR. 135 */ 136 H_STATUS_T Fn_AT24C02_ReadCurrentByte(uint8_t *pData) 137 { 138 H_PARA_ASSERT(pData == NULL); 139 140 if(HAL_OK != HAL_I2C_Master_Receive(&hi2c1, AT24C02_ADDR, pData, 1, 0xFF)) 141 { 142 return H_ERROR; 143 } 144 145 return H_SUCCESS; 146 } 147 148 149 /** 150 * @brief AT24C02 read a byte. 151 * @param addr, AT24C02 read data memory. 152 pData, Read data buffer. 153 * @retval H_SUCCESS or H_ERROR. 154 */ 155 H_STATUS_T Fn_AT24C02_ReadByte(uint8_t addr, uint8_t *pData) 156 { 157 H_PARA_ASSERT(pData == NULL); 158 159 if(HAL_OK != HAL_I2C_Mem_Read(&hi2c1, AT24C02_ADDR, addr, I2C_MEMADD_SIZE_8BIT, pData, 1, 0xFF)) 160 { 161 return H_ERROR; 162 } 163 164 return H_SUCCESS; 165 } 166 167 168 /** 169 * @brief AT24C02 read serial data. 170 * @param addr, AT24C02 read data memory. 171 pData, Read data buffer. 172 len, Read data length. 173 * @retval H_SUCCESS or H_ERROR. 174 */ 175 H_STATUS_T Fn_AT24C02_ReadData(uint8_t addr, uint8_t *pData, uint16_t len) 176 { 177 H_PARA_ASSERT((pData == NULL) || (len > AT24C02_MAX_BYTE_NUM));
178
179 if(HAL_OK != HAL_I2C_Mem_Read(&hi2c1, AT24C02_ADDR, addr, I2C_MEMADD_SIZE_8BIT, pData, len, 0xFFFF))
180 {
181 return H_ERROR;
182 }
183
184 return H_SUCCESS;
185 }
186
187
188 /**
189 * @brief AT24C02 clear memory data.
190 * @param None.
191 * @retval H_SUCCESS or H_ERROR.
192 */
193 H_STATUS_T Fn_AT24C02_ClearMemData(void)
194 {
195 uint32_t i = 0;
196 uint8_t page_addr = 0x00;
197 uint8_t data[AT24C02_PAGE_SIZE] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
198
199 for(i = 0; i < AT24C02_PAGE_NUM; i++)
200 {
201 if(H_SUCCESS != Fn_AT24C02_WritePage((H_AT24C02_PAGE_T)page_addr, data, AT24C02_PAGE_SIZE))
202 {
203 return H_ERROR;
204 }
205
206 page_addr += AT24C02_PAGE_SIZE;
207
208 /* For auto sync write */
209 Fn_DelayMs(5);
210 }
211
212 return H_SUCCESS;
213 }

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