STM32F1与STM32CubeIDE编程实例-设备驱动-EEPROM-AT24C256驱动

EEPROM-AT24C256驱动

1、EEPROM与AT24C256介绍

EEPROM（电可擦除可编程只读存储器）是用户可修改的只读存储器（ROM），可以通过施加高于正常电压的电压反复擦除和重新编程（写入）。 与 EPROM 芯片不同，EEPROM 不需要从计算机中取出即可进行修改。 但是，EEPROM 芯片必须整体擦除和重新编程，而不是选择性地擦除和重新编程。 它还具有有限的寿命——也就是说，它可以重新编程的次数被限制在数万或数十万次。 在计算机使用过程中经常重新编程的 EEPROM 中，EEPROM 的寿命可能是一个重要的设计考虑因素。

一种特殊形式的 EEPROM 是闪存，它使用正常的 PC 电压进行擦除和重新编程。

AT24C128/256 提供 131,072/262,144 位串行电可擦除可编程只读存储器 (EEPROM)，组织为 16,384/32,768 个字，每个字为 8 位。 该设备的级联功能允许多达 4 个设备共享一个公共的两线总线。 该器件针对许多工业和商业应用进行了优化，在这些应用中，低功率和低电压操作是必不可少的。 这些器件采用节省空间的 8 引线 JEDEC PDIP、8 引线 JEDEC SOIC、8 引线 EIAJSOIC、8 引线 MAP (24C128)、8 引线 TSSOP、8 引线 SOIC 阵列封装和 8 焊球 dBGA2 封装 . 此外，整个系列提供 2.7V（2.7V 至 5.5V）和 1.8V（1.8V 至 3.6V）版本。

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关于AT24Cxx的驱动在前面的文章做了详细的描述，请参考：

2、AT24C256配置

开发环境搭建、系统时钟配置、调试配置及串口配置，请参考：

2.1 AT24C256的I2C配置

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各项设置完成后，保存并生成代码。

3、AT24C256驱动实现

3.1 基本定义

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#ifndef \_AT24CXX\_H
#define \_AT24CXX\_H

#include "i2c.h"

#ifdef \_\_cplusplus
extern "C" {
#endif

#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>

typedef struct {
	uint16\_t id;
	I2C_HandleTypeDef\* i2c_handle;
	uint16\_t size_kb;
	uint8\_t device_address;
	uint16\_t p_size; // 页面大小
	bool is_locked;
}at24cxx\_t;

// 初始化
bool at24cxx\_init(at24cxx\_t\* device);
// 判断设备是否已经连接
bool at24cxx\_is\_connected(at24cxx\_t\* device);
// 在指定地址写数据
bool at24cxx\_write(at24cxx\_t\* device,uint16\_t address, uint8\_t \*data, size\_t len, uint32\_t timeout);
// 从指定地址读数据
bool at24cxx\_read(at24cxx\_t\* device,uint16\_t address, uint8\_t \*data, size\_t len, uint32\_t timeout);
// 芯片擦除
bool at24cxx\_erase\_chip(at24cxx\_t\* device);

#ifdef \_\_cplusplus
}
#endif

#endif


3.2 驱动功能实现

3.2.1 导入相关头文件
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// at24cxx.c
#include "at24cxx.h"
#include "main.h"
#include "i2c.h"

3.2.2 设备初始化
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bool at24cxx\_init(at24cxx\_t \*device) {
	switch (device->size_kb) {
	case 1:
	case 2:
		device->p_size = 8;
		break;
	case 4:
	case 8:
	case 16:
		device->p_size = 16;
		break;
	default:
		device->p_size = 32;
	}
	device->is_locked = false;
	return true;
}


3.2.2 判断设备是否连接
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// at24cxx.c
bool at24cxx\_is\_connected(at24cxx\_t \*device) {
	if (HAL\_I2C\_IsDeviceReady(device->i2c_handle, device->device_address, 2,
			100) == HAL_OK)
		return true;
	else
		return false;
}

函数HAL_I2C_IsDeviceReady用于判断I2C设备是否已经连接。如果已经连接，则返回true；否则，返回false。

3.2.3 写数据
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// at24cxx.c
bool at24cxx\_write(at24cxx\_t \*device, uint16\_t address, uint8\_t \*data,
		size\_t len, uint32\_t timeout) {
	if (device->is_locked)
		return false;

	device->is_locked = true;
	uint16\_t w;
	uint32\_t startTime = HAL\_GetTick();
	uint16\_t dev_address, mem_address, mem_add_size;
	mem_add_size = I2C_MEMADD_SIZE_8BIT;
	while (1) {
		w = device->p_size - (device->device_address % device->p_size);
		if (w > len) {
			w = len;
		}
		if (device->size_kb == 1 || device->size_kb == 2) {
			dev_address = device->device_address;
			mem_address = address;
		} else if (device->size_kb == 4) {
			dev_address = device->device_address | ((address & 0x0100) >> 7);
			mem_address = (address & 0xff);
		} else if (device->size_kb == 8) {
			dev_address = device->device_address | ((address & 0x0300) >> 7);
			mem_address = (address & 0xff);
		} else if (device->size_kb == 16) {
			dev_address = device->device_address | ((address & 0x0700) >> 7);
			mem_address = (address & 0xff);
		} else {
			dev_address = device->device_address;
			mem_address = address;
			mem_add_size = I2C_MEMADD_SIZE_16BIT;
		}
		if (HAL\_I2C\_Mem\_Write(device->i2c_handle, dev_address, mem_address,
				mem_add_size, data, w, 100) == HAL_OK) {
			HAL\_Delay(10);
			len -= w;
			data += w;
			address += w;
			if (len == 0) {
				device->is_locked = false;
				return true;
			}
			if (HAL\_GetTick() - startTime >= timeout) {
				device->is_locked = false;
				return false;
			}
		} else {
			device->is_locked = false;
			return false;
		}
	}
}

在上面代码中，主要步骤如下：

  • 1）通过储存页面大小和写入地址计算储存地址偏移值。
  • 2）使用HAL_I2C_Mem_Write函数写数据，并计算超时。
  • 3）重复1）和第2）步，直到指定数据长度写完。
3.2.3 读取数据
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// at24cxx.c
bool at24cxx\_read(at24cxx\_t \*device, uint16\_t address, uint8\_t \*data,
		size\_t len, uint32\_t timeout) {
	if (device->is_locked)
		return false;
	device->is_locked = true;
	uint16\_t dev_address, mem_address, mem_add_size;
	mem_add_size = I2C_MEMADD_SIZE_8BIT;

	if (device->size_kb == 1 || device->size_kb == 2) {
		dev_address = device->device_address;
		mem_address = address;
	} else if (device->size_kb == 4) {
		dev_address = device->device_address | ((address & 0x0100) >> 7);
		mem_address = (address & 0xff);
	} else if (device->size_kb == 8) {
		dev_address = device->device_address | ((address & 0x0300) >> 7);
		mem_address = (address & 0xff);
	} else if (device->size_kb == 16) {
		dev_address = device->device_address | ((address & 0x0700) >> 7);
		mem_address = (address & 0xff);
	} else {
		dev_address = device->device_address;
		mem_address = address;
		mem_add_size = I2C_MEMADD_SIZE_16BIT;
	}

	if (HAL\_I2C\_Mem\_Read(device->i2c_handle, dev_address, mem_address,
			mem_add_size, data, len, timeout) == HAL_OK) {
		device->is_locked = false;
		return true;
	} else {
		device->is_locked = false;
		return false;
	}
}

3.2.4 储存擦除
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// at24cxx.c
bool at24cxx\_erase\_chip(at24cxx\_t \*device) {
	const uint8\_t eraseData[32] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
			0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF\
, 0xFF, 0xFF,
			0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
			0xFF, 0xFF, 0xFF };
	uint32\_t bytes = 0;
	while (bytes < (device->size_kb\* 128)) {
		if (at24cxx\_write(device, bytes, (uint8\_t\*) eraseData,
				sizeof(eraseData), 100) == false)
			return false;
		bytes += sizeof(eraseData);
	}
	return true;
}

3.2.5 主程序
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// main.c
/\* USER CODE END Header \*/
/\* Includes ------------------------------------------------------------------\*/
#include "main.h"
#include "i2c.h"
#include "usart.h"
#include "gpio.h"

/\* Private includes ----------------------------------------------------------\*/
#include "AT24CXX/at24cxx.h"
#include <stdio.h>
/\* USER CODE END Includes \*/

/\* Private typedef -----------------------------------------------------------\*/
/\* USER CODE BEGIN PTD \*/
/\* USER CODE END PTD \*/

/\* Private define ------------------------------------------------------------\*/
/\* USER CODE BEGIN PD \*/
/\* USER CODE END PD \*/

/\* Private macro -------------------------------------------------------------\*/
/\* USER CODE BEGIN PM \*/

/\* USER CODE END PM \*/

/\* Private variables ---------------------------------------------------------\*/

/\* USER CODE BEGIN PV \*/

bool writeStatus = false;
bool readStatus = false;
bool eraseStatus = false;
uint8\_t wData[] = "Hello World 123";
uint8\_t rData[25];
/\* USER CODE END PV \*/

/\* Private function prototypes -----------------------------------------------\*/
void SystemClock\_Config(void);
/\* USER CODE BEGIN PFP \*/

/\* USER CODE END PFP \*/

/\* Private user code ---------------------------------------------------------\*/
/\* USER CODE BEGIN 0 \*/
at24cxx\_t at24cxx;
/\* USER CODE END 0 \*/

/\*\*
 \* @brief The application entry point.
 \* @retval int
 \*/
int main(void) {
	/\* USER CODE BEGIN 1 \*/

	/\* USER CODE END 1 \*/

	/\* MCU Configuration--------------------------------------------------------\*/

	/\* Reset of all peripherals, Initializes the Flash interface and the Systick. \*/
	HAL\_Init();

	/\* USER CODE BEGIN Init \*/

	/\* USER CODE END Init \*/

	/\* Configure the system clock \*/
	SystemClock\_Config();

	/\* USER CODE BEGIN SysInit \*/

	/\* USER CODE END SysInit \*/

	/\* Initialize all configured peripherals \*/
	MX\_GPIO\_Init();
	MX\_I2C1\_Init();
	MX\_USART1\_UART\_Init();
	/\* USER CODE BEGIN 2 \*/
	printf("AT24C256 EPPROM DEMO \r\n");
	at24cxx.i2c_handle = &hi2c1;
	at24cxx.id = 1;
	at24cxx.device_address = 0xA0;
	at24cxx.size_kb = 256; // 256Kb
	at24cxx\_init(&at24cxx);
	if(at24cxx\_is\_connected(&at24cxx)){
		if(at24cxx\_erase\_chip(&at24cxx)){
			printf("at24c256 erased\r\n");
		}else{
			printf("at24c256 erase failed\r\n");
		}
		if(at24cxx\_write(&at24cxx,MEM_ADDR, wData, 15, 100)){
			printf("write data:%s\r\n",wData);
		}else{
			printf("write data@0x00 failed\r\n");
		}
		if(at24cxx\_read(&at24cxx, MEM_ADDR, rData, 15, 100)){
			printf("read data from@0x00:%s\r\n ",rData);
		}else{
			printf("read data failed\r\n");
		}
	}else{
		printf("at24c256 not connected\r\n");
	}
	/\* USER CODE END 2 \*/

	/\* Infinite loop \*/
	/\* USER CODE BEGIN WHILE \*/
	while (1) {
		/\* USER CODE END WHILE \*/

		/\* USER CODE BEGIN 3 \*/
	}
	/\* USER CODE END 3 \*/
}


4、运行结果

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文章来源: https://iotsmart.blog.csdn.net/article/details/125238855