【GD32F303红枫派开发板使用手册】第二十一讲 I2C-EEPROM读写实验

聚沃科技 2024-06-21 1082

聚沃科技

168 内容 25w+阅读 16粉丝

描述

EEPROM

21.1 实验内容

通过本实验主要学习以下内容：

  • AT24C16 EEPROM的工作原理；
  • IIC模块原理以及IIC驱动原理。

21.2 实验原理

21.2.1 AT24C16 EEPROM的工作原理

下图为AT24CXX系列EEPROM相关参数，由该图可知，AT24C16的存储容量为16Kbit，共2048字节，共128页，每页为16字节。

EEPROM

由下图可知，AT24C16由8块组成，每块256字节。

EEPROM

I2C开始信号后，第一个字节为器件地址，由1010+3位块地址+1位读写标志组成， 3位块地址刚好可以表示 8个块， 所以一次写完256字节，换到下一下块的时候，要重新更改器件地址。

EEPROM

AT24C16支持页写入模式，一次最多可支持写入16字节。主机每发送一个字节，24c16收到确认，内部地址递增(仅限低4bit，所以1次可写16字节)。

21.2.2 IIC接口原理

GD32F30X系列MCU的I2C 接口模块实现了I2C 协议的标速模式，快速模式以及快速+模式，具备CRC 计算和校验功能、支持 SMBus（系统管理总线）和PMBus（电源管理总线），此外还支持多主机 I2C 总线架构，其主要特性如下：

◼ 并行总线至 I2C 总线协议的转换及接口；
◼ 同一接口既可实现主机功能又可实现从机功能；
◼ 主从机之间的双向数据传输；
◼ 支持 7 位和 10 位的地址模式和广播寻址；
◼ 支持 I2C 多主机模式；
◼ 支持标速（最高 100 KHz），快速（最高 400 KHz）和快速+ 模式（最高 1MHz）；
◼ 从机模式下可配置的 SCL 主动拉低；
◼ 支持 DMA 模式；
◼ 兼容 SMBus 2.0 和 PMBus；
◼ 两个中断：字节成功发送中断和错误事件中断；
◼ 可选择的 PEC（报文错误校验）生成和校验。  

IIC模块结构框图如下所示。

EEPROM

21.3 硬件设计

EEPROM硬件电路图如下所示，IIC引脚使用PB10和PB11引脚，SDA和SCL总线通过4.7K电阻上拉，且对地接30pf电容以及100欧姆串阻滤波。

EEPROMEEPROM

 

21.4 代码解析

21.4.1 EEPROM初始化配置函数

EEPROM初始化配置函数如下，主要实现对IIC总线引脚配置以及IIC模块配置。

C
void bsp_eeprom_init_AT24C16(void)
{
        driver_i2c_init(&EEPROM_I2C);
}
void driver_i2c_init(typdef_i2c_struct *i2cx)
{
    rcu_periph_clock_enable(i2cx->rcu_i2c_x);

    i2c_deinit(i2cx->i2c_x);
    
    driver_gpio_general_init(i2cx->i2c_scl_gpio);
    driver_gpio_general_init(i2cx->i2c_sda_gpio);        
    
    /* I2C clock configure */
    i2c_clock_config(i2cx->i2c_x, i2cx->frequency, I2C_DTCY_2);
    /* I2C address configure */
    i2c_mode_addr_config(i2cx->i2c_x, I2C_I2CMODE_ENABLE, I2C_ADDFORMAT_7BITS, i2cx->slave_addr);
    /* enable I2C0 */
    i2c_enable(i2cx->i2c_x);
    /* enable acknowledge */
    i2c_ack_config(i2cx->i2c_x, I2C_ACK_ENABLE);    
}

21.4.2 EEPROM buf写入接口函数

EEPROM buf写入接口函数实现如下，通过该函数可实现对AT24C16任意地址的多字节写入。内部已根据地址和写入长度自动识别从机地址以及对应的块，然后写入正确的地址空间。

C
EEPROM_STATE eeprom_buffer_write_AT24C16(uint8_t* p_buffer, uint16_t write_address, uint16_t number_of_byte)
{
          uint8_t number_of_page = 0, number_of_single = 0, address = 0, count = 0;
    uint8_t deviceId;
    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+write_address>EEPROM_SIZE)
                {
                        return EEPROM_ERROR;
                }
    /* if write_address is I2C_PAGE_SIZE aligned  */
    if(0 == address){
        while(number_of_page--){
                                        
                                          deviceId=(write_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((write_address>>7)&0x0E)):EEPROM_ADDR ;
            if(driver_i2c_mem_poll_write(&EEPROM_I2C,deviceId,write_address,MEM_ADDRESS_8BIT,p_buffer,I2C_PAGE_SIZE) == DRV_ERROR)
                                                {
                                                        return EEPROM_ERROR;
                                                }                                                        
            if(eeprom_wait_standby_state(&EEPROM_I2C) == EEPROM_ERROR)
                                                {
                                                        return EEPROM_ERROR;
                                                }
            write_address +=  I2C_PAGE_SIZE;
            p_buffer += I2C_PAGE_SIZE;
        }
        if(0 != number_of_single){
                                         deviceId=(write_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((write_address>>7)&0x0E)):EEPROM_ADDR ;
           if(driver_i2c_mem_poll_write(&EEPROM_I2C,deviceId,write_address,MEM_ADDRESS_8BIT,p_buffer, number_of_single)==DRV_ERROR)
                                         {
                                                 return EEPROM_ERROR;
                                         }
           if(eeprom_wait_standby_state(&EEPROM_I2C) == EEPROM_ERROR)
                                         {
                                                 return EEPROM_ERROR;
                                         }
        }
        return         EEPROM_SUCCESS;                        
    }else{
        /* if write_address is not I2C_PAGE_SIZE aligned */
        if(number_of_byte < count){ 
                                        deviceId=(write_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((write_address>>7)&0x0E)):EEPROM_ADDR ;
                                        if(driver_i2c_mem_poll_write(&EEPROM_I2C,deviceId,write_address,MEM_ADDRESS_8BIT,p_buffer, number_of_byte)==DRV_ERROR)
                                        {
                                                return EEPROM_ERROR;
                                        }
                                        if(eeprom_wait_standby_state(&EEPROM_I2C)==EEPROM_ERROR)
                                        {
                                                return EEPROM_ERROR;
                                        }
                                        
        }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){
                                                          deviceId=(write_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((write_address>>7)&0x0E)):EEPROM_ADDR ;
                                              if(driver_i2c_mem_poll_write(&EEPROM_I2C,deviceId,write_address,MEM_ADDRESS_8BIT,p_buffer, count)==DRV_ERROR)
                                                                {
                                                                        return EEPROM_ERROR;
                                                                }
                                                          if(eeprom_wait_standby_state(&EEPROM_I2C)==EEPROM_ERROR)
                                                                {
                                                                        return EEPROM_ERROR;
                                                                }
                write_address += count;
                p_buffer += count;
            } 
            /* write page */
            while(number_of_page--){
                                                          deviceId=(write_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((write_address>>7)&0x0E)):EEPROM_ADDR ;
                                              if(driver_i2c_mem_poll_write(&EEPROM_I2C,deviceId,write_address,MEM_ADDRESS_8BIT,p_buffer, I2C_PAGE_SIZE)==DRV_ERROR)
                                                                {
                                                                        return EEPROM_ERROR;
                                                                }
                                                          if(eeprom_wait_standby_state(&EEPROM_I2C)==EEPROM_ERROR)
                                                                {
                                                                        return EEPROM_ERROR;
                                                                }
                write_address +=  I2C_PAGE_SIZE;
                p_buffer += I2C_PAGE_SIZE;
            }
            /* write single */
            if(0 != number_of_single){
                                                          deviceId=(write_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((write_address>>7)&0x0E)):EEPROM_ADDR ;
                                              if(driver_i2c_mem_poll_write(&EEPROM_I2C,deviceId,write_address,MEM_ADDRESS_8BIT,p_buffer, number_of_single)==DRV_ERROR)
                                                                {
                                                                        return EEPROM_ERROR;
                                                                }
                                                          if(eeprom_wait_standby_state(&EEPROM_I2C)==EEPROM_ERROR)
                                                                {
                                                                        return EEPROM_ERROR;
                                                                }
            }
        }
                                return         EEPROM_SUCCESS;        
    }  
}

21.4.3 EEPROM buf读取接口函数

EEPROM buf读取接口函数实现如下，通过该函数可实现对EEPROM任意地址的多字节数据读取，内部也对读取的地址进行自动识别从机地址。

C
EEPROM_STATE eeprom_buffer_read_AT24C16(uint8_t* p_buffer, uint16_t read_address, uint16_t number_of_byte)
{
        uint8_t rNum=0; //读取的数据长度
        uint16_t lenLeft=number_of_byte;//剩余的数据长度
  uint8_t deviceId;//读取的器件地址
        if(read_address+number_of_byte>EEPROM_SIZE)//如果读取的长度加上读取地址超过了EEPROM的空间大小，则报错误
        {
                return EEPROM_ERROR;
        }
                /*calculate the current read position to know how many word can read continully*/
        rNum=16-read_address & 0x0F;
        if(rNum == 0)  rNum=16;
        rNum = lenLeft>=rNum ? rNum : lenLeft;//剩余未读字节数如果大于rNum, 则读rNum个，如果小于rNum，则一次读完了
        /*read the data from e2prom*/
        while(lenLeft)
        {
                //这里计算页地址，当地址小于256时，右移8位会小于0，所以器件地址为基地址A1
                //如果读取的地址大于256时，右移8位则不会小于0，所以器件地址为 基地址A1 | 3位页地址
    deviceId=(read_address>>8)>0 ? (EEPROM_ADDR | (uint8_t)((read_address>>7)&0x0E)):EEPROM_ADDR ;

                if(driver_i2c_mem_poll_read(&EEPROM_I2C,deviceId,read_address,MEM_ADDRESS_8BIT,p_buffer,rNum)==DRV_ERROR)
                {
//                        printf("i2c read error\r\n");
                          return EEPROM_ERROR;
                }
                read_address+=rNum;//已经读了rNum个了，所以地址后移rNum个
                lenLeft-=rNum;//剩余未读数据减少rNum个
                p_buffer+=rNum;
                rNum=lenLeft>16? 16 : lenLeft;//如果剩余大于16个，则下次再读16个，如果小于，则一次读完
        }
  return EEPROM_SUCCESS;
}

21.4.4 EEPROM读写实验主函数

EEPROM读写实验主函数如下所示。通过该实验实现对AT24C16任意地址256字节的写入、读取以及校验测试。

C
int main(void)
{
          uint16_t i;
    uint8_t i2c_buffer_write[BUFFER_SIZE];
    uint8_t i2c_buffer_read[BUFFER_SIZE];
        
    bsp_eeprom_init_AT24C16();
    /* initialize i2c_buffer_write */
    for(i = 0;i < BUFFER_SIZE;i++){ 
        i2c_buffer_write[i]=i;
//        printf("0x%02X ",i2c_buffer_write[i]);
//        if(15 == i%16){
//            printf("\r\n");
//        }
    }
                
                if(eeprom_buffer_write_AT24C16(i2c_buffer_write,0x0153,BUFFER_SIZE)==EEPROM_SUCCESS)
                {
                        __nop();
                }
                if(eeprom_buffer_read_AT24C16(i2c_buffer_read,0x0153,BUFFER_SIZE)==EEPROM_SUCCESS)
                {
                        __nop();
                }
                    /* compare the read buffer and write buffer */
    for(i = 0;i < BUFFER_SIZE;i++){
        if(i2c_buffer_read[i] != i2c_buffer_write[i]){
                                        __nop();
//            printf("0x%02X ", i2c_buffer_read[i]);
//            printf("Err:data read and write aren't matching.\n\r");
//            return I2C_FAIL;
        }
        //printf("0x%02X ", i2c_buffer_read[i]);
//        if(15 == i%16){
//            printf("\r\n");
//        }
    }
                __nop();
//    printf("I2C-AT24C02 test passed!\n\r");
        while (1)
        {
        }
}

21.5 实验结果

将本实验历程烧录到红枫派开发板中，运行后，可通过串口打印测试结果，可实现对于AT24C16任意地址写入、读取以及校验。

EEPROM

 

本教程由GD32 MCU方案商聚沃科技原创发布，了解更多GD32 MCU教程，关注聚沃科技官网

 

打开APP阅读更多精彩内容
声明：本文内容及配图由入驻作者撰写或者入驻合作网站授权转载。文章观点仅代表作者本人，不代表电子发烧友网立场。文章及其配图仅供工程师学习之用，如有内容侵权或者其他违规问题，请联系本站处理。 举报投诉

全部0条评论

快来发表一下你的评论吧 !

下载APP
|投诉反馈|电子发烧友网
© 2021 elecfans.com
湘ICP备2023018690号
×
20
完善资料，
赚取积分