单片机GD32F303RCT6 (Macos环境)开发 （十六）—— Eeprom AT24C08的读取_at24c08一次可以读几个字节

1、AT24C04 、AT24C08、AT24C016应该都适应这份代码，他们每一页的大小都是16字节。如果是AT24C02的话，每一页的大小为8个字节，修改一下#define I2C_PAGE_SIZE 8 应该也可以正常换页读取。
2、关于代码的宏定义配置
Application目录的Makefile中 ENABLE_I2C_TEST = yes才会编译I2C1的相关代码。
同时修改i2c.h文件，定义I2C1_MODE为I2C1_MODE_POLL，at24c08 .c 相关代码才会编译进去。
3、At24C08.c 核心就是一个换页写入的操作，因为eeprom连续写入时不支持自动换页，但是连续读取时，是可以自动换页的。

#include "gd32f30x.h"
#include "systick.h"
#include "at24c08.h"
#include "i2c.h"

#if I2C1_MODE == I2C1_MODE_POLL 

#define I2C1_SPEED                          100000
#define EE_ADDR   							0xA0 
#define I2C_PAGE_SIZE                       16


/*!
    \brief      write one byte to the I2C EEPROM
    \param[in]  p_buffer: pointer to the buffer containing the data to be written to the EEPROM
    \param[in]  write_address: EEPROM's internal address to write to
    \param[out] none
    \retval     none
*/
void eeprom_byte_write(uint8_t Data, uint8_t write_address)
{
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));

    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C1);
    
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND));
    
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C1, EE_ADDR, I2C_TRANSMITTER);
    
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));
    
    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C1,I2C_FLAG_ADDSEND);
    
    /* wait until the transmit data buffer is empty */
    while(SET != i2c_flag_get(I2C1, I2C_FLAG_TBE));
    
    /* send the EEPROM's internal address to write to : only one byte address */
    i2c_data_transmit(I2C1, write_address);
    
    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));
    
    /* send the byte to be written */
    i2c_data_transmit(I2C1, Data); 
    
    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));

    /* send a stop condition to I2C bus */
    i2c_stop_on_bus(I2C1);
    
    /* wait until the stop condition is finished */
    while(I2C_CTL0(I2C1)&0x0200);
}

/*!
    \brief      write more than one byte to the EEPROM with a single write cycle
    \param[in]  p_buffer: pointer to the buffer containing the data to be written to the EEPROM
    \param[in]  write_address: EEPROM's internal address to write to
    \param[in]  number_of_byte: number of bytes to write to the EEPROM
    \param[out] none
    \retval     none
*/
void eeprom_page_write(uint8_t* p_buffer, uint8_t write_address, uint8_t number_of_byte)
{
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));
    
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C1);
    
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND));
    
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C1, EE_ADDR, I2C_TRANSMITTER);
    
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));
    
    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C1,I2C_FLAG_ADDSEND);
    
    /* wait until the transmit data buffer is empty */
    while( SET != i2c_flag_get(I2C1, I2C_FLAG_TBE));
    
    /* send the EEPROM's internal address to write to : only one byte address */
    i2c_data_transmit(I2C1, write_address);
    
    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));
    
    /* while there is data to be written */
    while(number_of_byte--){  
        i2c_data_transmit(I2C1, *p_buffer);
        
        /* point to the next byte to be written */
        p_buffer++; 
        
        /* wait until BTC bit is set */
        while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));
    }
    /* send a stop condition to I2C bus */
    i2c_stop_on_bus(I2C1);
    
    /* wait until the stop condition is finished */
    while(I2C_CTL0(I2C1)&0x0200);
}

/*!
    \brief      read data from the EEPROM
    \param[in]  p_buffer: pointer to the buffer that receives the data read from the EEPROM
    \param[in]  read_address: EEPROM's internal address to start reading from
    \param[in]  number_of_byte: number of bytes to reads from the EEPROM
    \param[out] none
    \retval     none
*/
void eeprom_buffer_read(uint8_t* p_buffer, uint8_t read_address, uint16_t number_of_byte)
{  
    /* wait until I2C bus is idle */
    while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));

    if(2 == number_of_byte){
        i2c_ackpos_config(I2C1,I2C_ACKPOS_NEXT);
    }
    
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C1);
    
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND));
    
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C1, EE_ADDR, I2C_TRANSMITTER);
    
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));
    
    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C1,I2C_FLAG_ADDSEND);
    
    /* wait until the transmit data buffer is empty */
    while(SET != i2c_flag_get( I2C1 , I2C_FLAG_TBE));

    /* enable I2C1*/
    i2c_enable(I2C1);
    
    /* send the EEPROM's internal address to write to */
    i2c_data_transmit(I2C1, read_address);  
    
    /* wait until BTC bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));
    
    /* send a start condition to I2C bus */
    i2c_start_on_bus(I2C1);
    
    /* wait until SBSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND));
    
    /* send slave address to I2C bus */
    i2c_master_addressing(I2C1, EE_ADDR, I2C_RECEIVER);

    if(number_of_byte < 3){
        /* disable acknowledge */
        i2c_ack_config(I2C1,I2C_ACK_DISABLE);
    }
    
    /* wait until ADDSEND bit is set */
    while(!i2c_flag_get(I2C1, I2C_FLAG_ADDSEND));
    
    /* clear the ADDSEND bit */
    i2c_flag_clear(I2C1,I2C_FLAG_ADDSEND);
    
    if(1 == number_of_byte){
        /* send a stop condition to I2C bus */
        i2c_stop_on_bus(I2C1);
    }
    
    /* while there is data to be read */
    while(number_of_byte){
        if(3 == number_of_byte){
            /* wait until BTC bit is set */
            while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));

            /* disable acknowledge */
            i2c_ack_config(I2C1,I2C_ACK_DISABLE);
        }
        if(2 == number_of_byte){
            /* wait until BTC bit is set */
            while(!i2c_flag_get(I2C1, I2C_FLAG_BTC));
            
            /* send a stop condition to I2C bus */
            i2c_stop_on_bus(I2C1);
        }
        
        /* wait until the RBNE bit is set and clear it */
        if(i2c_flag_get(I2C1, I2C_FLAG_RBNE)){
            /* read a byte from the EEPROM */
            *p_buffer = i2c_data_receive(I2C1);
            
            /* point to the next location where the byte read will be saved */
            p_buffer++; 
            
            /* decrement the read bytes counter */
            number_of_byte--;
        } 
    }
    
    /* wait until the stop condition is finished */
    while(I2C_CTL0(I2C1)&0x0200);
    
    /* enable acknowledge */
    i2c_ack_config(I2C1,I2C_ACK_ENABLE);

    i2c_ackpos_config(I2C1,I2C_ACKPOS_CURRENT);
}

/*!
    \brief      wait for EEPROM standby state
    \param[in]  none
    \param[out] none
    \retval     none
*/
void eeprom_wait_standby_state(void)
{
    __IO uint32_t val = 0;
    
    while(1){
        /* wait until I2C bus is idle */
        while(i2c_flag_get(I2C1, I2C_FLAG_I2CBSY));
        
        /* send a start condition to I2C bus */
        i2c_start_on_bus(I2C1);
        
        /* wait until SBSEND bit is set */
        while(!i2c_flag_get(I2C1, I2C_FLAG_SBSEND));
        
        /* send slave address to I2C bus */
        i2c_master_addressing(I2C1, EE_ADDR, I2C_TRANSMITTER);
        
        /* keep looping till the Address is acknowledged or the AE flag is set (address not acknowledged at time) */
        do{
            /* get the current value of the I2C_STAT0 register */
            val = I2C_STAT0(I2C1);
            
        }while(0 == (val & (I2C_STAT0_ADDSEND | I2C_STAT0_AERR)));
         
        /* check if the ADDSEND flag has been set */
        if(val & I2C_STAT0_ADDSEND){
            
            /* clear ADDSEND flag */
            i2c_flag_clear(I2C1,I2C_FLAG_ADDSEND);
            
            /* send a stop condition to I2C bus */
            i2c_stop_on_bus(I2C1);
            
            /* exit the function */
            return ;
            
        }else{
            /* clear the bit of AE */
            i2c_flag_clear(I2C1,I2C_FLAG_AERR);
        }
        
        /* send a stop condition to I2C bus */
        i2c_stop_on_bus(I2C1);
        /* wait until the stop condition is finished */
        while(I2C_CTL0(I2C1)&0x0200);
    }
}

/*!
    \brief      write buffer of data to the I2C EEPROM
    \param[in]  p_buffer: pointer to the buffer  containing the data to be written to the EEPROM
    \param[in]  write_address: EEPROM's internal address to write to
    \param[in]  number_of_byte: number of bytes to write to the EEPROM
    \param[out] none
    \retval     none
*/
void eeprom_buffer_write(uint8_t* p_buffer, uint8_t write_address, uint16_t number_of_byte)
{
    uint8_t number_of_page = 0, number_of_single = 0, address = 0, count = 0;
    
    address = write_address % I2C_PAGE_SIZE;
    count = I2C_PAGE_SIZE - address;
    number_of_page =  number_of_byte / I2C_PAGE_SIZE;
    number_of_single = number_of_byte % I2C_PAGE_SIZE;
    
    /* if write_address is I2C_PAGE_SIZE aligned  */
    if(0 == address){
        while(number_of_page--){
            eeprom_page_write(p_buffer, write_address, I2C_PAGE_SIZE); 
            eeprom_wait_standby_state();
            write_address +=  I2C_PAGE_SIZE;
            p_buffer += I2C_PAGE_SIZE;
        }
        if(0 != number_of_single){
            eeprom_page_write(p_buffer, write_address, number_of_single);
            eeprom_wait_standby_state();
        }      
    }else{
        /* if write_address is not I2C_PAGE_SIZE aligned */
        if(number_of_byte < count){ 
            eeprom_page_write(p_buffer, write_address, number_of_byte);
            eeprom_wait_standby_state();
        }else{
            number_of_byte -= count;
            number_of_page =  number_of_byte / I2C_PAGE_SIZE;
            number_of_single = number_of_byte % I2C_PAGE_SIZE;
            
            if(0 != count){
                eeprom_page_write(p_buffer, write_address, count);
                eeprom_wait_standby_state();
                write_address += count;
                p_buffer += count;
            } 
            /* write page */
            while(number_of_page--){
                eeprom_page_write(p_buffer, write_address, I2C_PAGE_SIZE);
                eeprom_wait_standby_state();
                write_address +=  I2C_PAGE_SIZE;
                p_buffer += I2C_PAGE_SIZE;
            }
            /* write single */
            if(0 != number_of_single){
                eeprom_page_write(p_buffer, write_address, number_of_single); 
                eeprom_wait_standby_state();
            }
        }
    }  
}

#endif //#if I2C1_MODE == I2C1_MODE_POLL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339

at24c08.h

/*
**------------------------------------------------------------------------------------------------------
** Modified by:			
** Modified date:	
** Version:
** Descriptions:		
********************************************************************************************************/
#ifndef __24C08_H
#define __24C08_H
#include "i2c.h"

#if I2C1_MODE == I2C1_MODE_POLL
/* Private function prototypes -----------------------------------------------*/
void eeprom_buffer_read(uint8_t* p_buffer, uint8_t read_address, uint16_t number_of_byte);
void eeprom_buffer_write(uint8_t* p_buffer, uint8_t write_address, uint16_t number_of_byte);
#endif  //#if I2C1_MODE == I2C1_MODE_POLL
#endif //__24C08_H
/*********************************************************************************************************
      END FILE
*********************************************************************************************************/
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

i2c1de 初始化在 i2c1.c中

/**
 * PB10 PB11 config I2C1
*/
void i2c1_config(void)
{
    /* enable GPIOB clock */
    rcu_periph_clock_enable(RCU_GPIOB);
    /* enable I2C1 clock */
    rcu_periph_clock_enable(RCU_I2C1);
    /* connect PB10 to I2C1_SCL */
    /* connect PB11 to I2C2_SDA */
    gpio_init(GPIOB, GPIO_MODE_AF_OD, GPIO_OSPEED_50MHZ, GPIO_PIN_10 | GPIO_PIN_11);//配置PB10,PB11为复用功能

    /* configure I2C clock */
    i2c_clock_config(I2C1, I2C1_SPEED, I2C_DTCY_2);
    /* configure I2C address */
    i2c_mode_addr_config(I2C1, I2C_I2CMODE_ENABLE, I2C_ADDFORMAT_7BITS, I2C1_SLAVE_ADDR);
    /* enable I2C1 */
    i2c_enable(I2C1);
    /* enable acknowledge */
    i2c_ack_config(I2C1, I2C_ACK_ENABLE);
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22

4、主函数调用，我们连续写入一个字符串，超过16个字节，然后读取，看是否一致

    char r_buff[48] = {0};  
    char *buff = "hello world,GD32F330RCT6!";
    eeprom_buffer_write(r_buff,0,sizeof(r_buff)); //清零
    delay_1ms(200);
    eeprom_buffer_write(buff,0,strlen(buff));
    delay_1ms(200);
    
    eeprom_buffer_read(r_buff,0,48);
    printf("read data form eeprom = %s\r\n",r_buff);
1
2
3
4
5
6
7
8
9

5、开机打印信息如下：

6 、代码路径：https://gitee.com/xiaoguo-tec_0/gd32-iap-code.git