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STM32:I2C接口读写EEPROM(AT24C02)试验例程

2017-04-24 18:42 639 查看
硬件平台:stm32f10xZET6
开发环境:keil MDK uVisionv4.10
开发语言:C、ST_lib_3.5固件库

EEPROM:电可擦可编程只读存储器。

【stm32f10xZET6开发板的I2C外设物理层特点】

(1)两条串行总线:一条双向数据线(SDA),一条时钟线(SCL);

(2)从设备地址唯一;

(3)支持总线仲裁;

(4)三种速率传输模式:

    标准模式100kbit/s

    快速模式400kbit/s

    高速模式3.4Mbit/s (目前大多I2C设备尚不支持高速模式)

(5)片上的滤波器可以滤去总线数据线上的毛刺波保证数据完整;

(6)连接到相同总线的IC数量受到总线的最大电容400pF限制;

【I2C接口特性】

(1) STM32 中和大容量型号芯片均有多达 2 个I2C总线接口;

(2) 能够工作于多主机或多从机模式,主从均可收发;

(3) 支持标准模式 100Kbit/s 和快速模式 400Kbit/s,不支持高

速模式;

(4) 支持 7 位或 10 位从设备地址寻址;

(5) 内置了硬件 CRC 发生器/ 校验器;

(6) I2C 的接收和发送都可以使用 DMA 操作;

(7) 支持系统管理总线(SMBus)总线 2.0 版;

typedef struct

{

  uint32_t I2C_ClockSpeed;          /*!< 指定时钟总线速率,100/400kHz */

  uint16_t I2C_Mode;                /*!< 指定为I2C通信模式 */

  uint16_t I2C_DutyCycle;           /*!< 指定I2C快速模式 */

  uint16_t I2C_OwnAddress1;         /*!< 指定从设备自身地址,7/10bit(地址0x0A对应宏) */

  uint16_t I2C_Ack;                 /*!< 使能或禁止ack */

  uint16_t I2C_AcknowledgedAddress; /*!< 指定7/10bit从设备地址下的ack */

} I2C_InitTypeDef;

在 stm32 如何建立与 EEPROM 的通讯步骤:

(1) 配置 I/O 端口,确定并配置 I2C 的模式,使能 GPIO 和 I2C

时钟。

(2) 写:

    1) 检测 SDA 是否空闲;

    2) 按 I2C 协议发出起始信号;

    3) 发出 7 位器件地址和写模式;

    4) 要写入的存储区首地址;

    5) 用页写入方式或字节写入方式写入数据;

    6) 发送 I2C 通讯结束讯信号

每个操作之后要检测“事件”确定是否成功。写完后检测 EEPROM 是否进

入 standby 状态。

(3) 读:

    1) 检测 SDA 是否空闲;

    2) 按 I2C 协议发出起始讯号;

    3) 发出 7 位器件地址和写模式(伪写);

    4) 发出要读取的存储区首地址;

    5) 重发起始讯号;第 260 页 共 729 页

    6) 发出 7 位器件地址和读模式;

    7) 接收数据;

类似写操作,每个操作之后要检测“事件”确定是否成功。

I2C_GenerateSTART();    // 产生 I2C 的通讯起始信号 S

I2C_Send7bitAddress();  // 发送7位从设备地址

I2C_SendData();         // 发送一个数据字节(8bit)

I2C_GenerateSTOP();     // 产生 I2C 的通讯停止信号 P

I2C_CheckEvent ();      // I2C 传输时的事件监测

/* 代码演示 - mian.c */
/**
******************************************************************************
* @file    main.c
* @author  fire
* @version V1.0
* @date    2013-xx-xx
* @brief   I2C EEPROM(AT24C02)测试,测试信息通过USART1打印在电脑的超级终端
******************************************************************************
*/

#include "stm32f10x.h"
#include "bsp_usart1.h"
#include "bsP_i2c_ee.h"
#include "bsP_led.h"
#include <string.h>

#define  EEP_Firstpage      0x00
u8 I2c_Buf_Write[256];
u8 I2c_Buf_Read[256];
void I2C_Test(void);

/**
* @brief  主函数
* @param  无
* @retval 无
*/
int main(void)
{

/* 串口1初始化 */
USART1_Config();

printf("\r\n 这是一个I2C外设(AT24C02)读写测试例程 \r\n");
//LED_GPIO_Config();

/* I2C 外设初(AT24C02)始化 */
I2C_EE_Init();

printf("\r\n 这是一个I2C外设(AT24C02)读写测试例程 \r\n");

I2C_Test();

while (1)
{
}
}

/**
* @brief  I2C(AT24C02)读写测试
* @param  无
* @retval 无
*/
void I2C_Test(void)
{
u16 i;

printf("写入的数据\n\r");

for ( i=0; i<=255; i++ ) // 填充缓冲
{
I2c_Buf_Write[i] = i;

printf("0x%02X ", I2c_Buf_Write[i]);
if(i%16 == 15)
printf("\n\r");
}

//将I2c_Buf_Write中顺序递增的数据写入EERPOM中
//LED1(ON);
I2C_EE_BufferWrite (I2c_Buf_Write, EEP_Firstpage, 256);
//LED1(OFF);

printf("\n\r写成功\n\r");

printf("\n\r读出的数据\n\r");
//将EEPROM读出数据顺序保持到I2c_Buf_Read中
//LED2(ON);
I2C_EE_BufferRead(I2c_Buf_Read, EEP_Firstpage, 256);
//LED2(OFF);

//将I2c_Buf_Read中的数据通过串口打印
for (i=0; i<256; i++)
{
if(I2c_Buf_Read[i] != I2c_Buf_Write[i])
{
printf("0x%02X ", I2c_Buf_Read[i]);
printf("错误:I2C EEPROM写入与读出的数据不一致\n\r");
return;
}
printf("0x%02X ", I2c_Buf_Read[i]);
if(i%16 == 15)
printf("\n\r");

}
printf("I2C(AT24C02)读写测试成功\n\r");
}

/* 代码演示 - bsp_i2c_ee模块 */
#ifndef __I2C_EE_H
#define	__I2C_EE_H

#include "stm32f10x.h"

/*
* AT24C02 2kb = 2048bit = 2048/8 B = 256 B
* 32 pages of 8 bytes each
*
* Device Address
* 1 0 1 0 A2 A1 A0 R/W
* 1 0 1 0 0  0  0  0 = 0XA0
* 1 0 1 0 0  0  0  1 = 0XA1
*/

/* EEPROM Addresses defines */
#define EEPROM_Block0_ADDRESS   0xA0 /* E2 = 0 */
//#define EEPROM_Block1_ADDRESS 0xA2 /* E2 = 0 */
//#define EEPROM_Block2_ADDRESS 0xA4 /* E2 = 0 */
//#define EEPROM_Block3_ADDRESS 0xA6 /* E2 = 0 */

void I2C_EE_Init(void);
void I2C_EE_BufferWrite(u8* pBuffer, u8 WriteAddr, u16 NumByteToWrite);
void I2C_EE_ByteWrite(u8* pBuffer, u8 WriteAddr);
void I2C_EE_PageWrite(u8* pBuffer, u8 WriteAddr, u8 NumByteToWrite);
void I2C_EE_BufferRead(u8* pBuffer, u8 ReadAddr, u16 NumByteToRead);
void I2C_EE_WaitEepromStandbyState(void);

#endif /* __I2C_EE_H */

//--------------------------------------------------------
/**
******************************************************************************
* @file    bsp_i2c_ee.c
* @author  STMicroelectronics
* @version V1.0
* @date    2013-xx-xx
* @brief   i2c EEPROM(AT24C02)应用函数bsp
******************************************************************************
*/

#include "bsp_i2c_ee.h"

/* STM32 I2C 快速模式 */
#define I2C_Speed              400000

/* 这个地址只要与STM32外挂的I2C器件地址不一样即可 */
#define I2C1_OWN_ADDRESS7      0X0A

/* AT24C01/02每页有8个字节 */
#define I2C_PageSize           8

/* AT24C04/08A/16A每页有16个字节 */
//#define I2C_PageSize           16

uint16_t EEPROM_ADDRESS;

/**
* @brief  I2C1 I/O配置
* @param  无
* @retval 无
*/
static void I2C_GPIO_Config(void)
{
GPIO_InitTypeDef  GPIO_InitStructure;

/* 使能与 I2C1 有关的时钟 */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1,ENABLE);

/* PB6-I2C1_SCL、PB7-I2C1_SDA*/
GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;	       // 开漏输出
GPIO_Init(GPIOB, &GPIO_InitStructure);
}

/**
* @brief  I2C 工作模式配置
* @param  无
* @retval 无
*/
static void I2C_Mode_Configu(void)
{
I2C_InitTypeDef  I2C_InitStructure;

/* I2C 配置 */
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;

/* 高电平数据稳定,低电平数据变化 SCL 时钟线的占空比 */
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;

I2C_InitStructure.I2C_OwnAddress1 = I2C1_OWN_ADDRESS7;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable ;

/* I2C的寻址模式 */
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;

/* 通信速率 */
I2C_InitStructure.I2C_ClockSpeed = I2C_Speed;

/* I2C1 初始化 */
I2C_Init(I2C1, &I2C_InitStructure);

/* 使能 I2C1 */
I2C_Cmd(I2C1, ENABLE);
}

/**
* @brief  I2C 外设(EEPROM)初始化
* @param  无
* @retval 无
*/
void I2C_EE_Init(void)
{

I2C_GPIO_Config();

I2C_Mode_Configu();

/* 根据头文件i2c_ee.h中的定义来选择EEPROM要写入的地址 */
#ifdef EEPROM_Block0_ADDRESS
/* 选择 EEPROM Block0 来写入 */
EEPROM_ADDRESS = EEPROM_Block0_ADDRESS;
#endif

#ifdef EEPROM_Block1_ADDRESS
/* 选择 EEPROM Block1 来写入 */
EEPROM_ADDRESS = EEPROM_Block1_ADDRESS;
#endif

#ifdef EEPROM_Block2_ADDRESS
/* 选择 EEPROM Block2 来写入 */
EEPROM_ADDRESS = EEPROM_Block2_ADDRESS;
#endif

#ifdef EEPROM_Block3_ADDRESS
/* 选择 EEPROM Block3 来写入 */
EEPROM_ADDRESS = EEPROM_Block3_ADDRESS;
#endif
}

/**
* @brief   将缓冲区中的数据写到I2C EEPROM中
* @param
*		@arg pBuffer:缓冲区指针
*		@arg WriteAddr:写地址
*     @arg NumByteToWrite:写的字节数
* @retval  无
*/
void I2C_EE_BufferWrite(u8* pBuffer, u8 WriteAddr, u16 NumByteToWrite)
{
u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0;

Addr = WriteAddr % I2C_PageSize;              // addr = 8bit % 8
count = I2C_PageSize - Addr;                  // 8 - addr
NumOfPage =  NumByteToWrite / I2C_PageSize;
NumOfSingle = NumByteToWrite % I2C_PageSize;

/* If WriteAddr is I2C_PageSize aligned  */
if(Addr == 0)
{
/* If NumByteToWrite < I2C_PageSize */
if(NumOfPage == 0)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
I2C_EE_WaitEepromStandbyState();
}
/* If NumByteToWrite > I2C_PageSize */
else
{
while(NumOfPage--)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize);
I2C_EE_WaitEepromStandbyState();
WriteAddr +=  I2C_PageSize;
pBuffer += I2C_PageSize;
}

if(NumOfSingle!=0)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
I2C_EE_WaitEepromStandbyState();
}
}
}
/* If WriteAddr is not I2C_PageSize aligned  */
else
{
/* If NumByteToWrite < I2C_PageSize */
if(NumOfPage== 0)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
I2C_EE_WaitEepromStandbyState();
}
/* If NumByteToWrite > I2C_PageSize */
else
{
NumByteToWrite -= count;
NumOfPage =  NumByteToWrite / I2C_PageSize;
NumOfSingle = NumByteToWrite % I2C_PageSize;

if(count != 0)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, count);
I2C_EE_WaitEepromStandbyState();
WriteAddr += count;
pBuffer += count;
}

while(NumOfPage--)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize);
I2C_EE_WaitEepromStandbyState();
WriteAddr +=  I2C_PageSize;
pBuffer += I2C_PageSize;
}
if(NumOfSingle != 0)
{
I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
I2C_EE_WaitEepromStandbyState();
}
}
}
}

/**
* @brief   写一个字节到I2C EEPROM中
* @param
*		@arg pBuffer:缓冲区指针
*		@arg WriteAddr:写地址
* @retval  无
*/
void I2C_EE_ByteWrite(u8* pBuffer, u8 WriteAddr)
{
/* Send STRAT condition */
I2C_GenerateSTART(I2C1, ENABLE);

/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for write */
I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);

/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

/* Send the EEPROM's internal address to write to */
I2C_SendData(I2C1, WriteAddr);

/* Test on EV8 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

/* Send the byte to be written */
I2C_SendData(I2C1, *pBuffer);

/* Test on EV8 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

/* Send STOP condition */
I2C_GenerateSTOP(I2C1, ENABLE);
}

/**
* @brief   在EEPROM的一个写循环中可以写多个字节,但一次写入的字节数
*          不能超过EEPROM页的大小,AT24C02每页有8个字节
* @param
*		@arg pBuffer:缓冲区指针
*		@arg WriteAddr:写地址
*     @arg NumByteToWrite:写的字节数
* @retval  无
*/
void I2C_EE_PageWrite(u8* pBuffer, u8 WriteAddr, u8 NumByteToWrite)
{
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY)); // Added by Najoua 27/08/2008

/* 发送start信号 */
I2C_GenerateSTART(I2C1, ENABLE);

/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for write */
I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);

/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

/* Send the EEPROM's internal address to write to */
I2C_SendData(I2C1, WriteAddr);

/* Test on EV8 and clear it */
while(! I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

/* While there is data to be written */
while(NumByteToWrite--)
{
/* Send the current byte */
I2C_SendData(I2C1, *pBuffer);

/* Point to the next byte to be written */
pBuffer++;

/* Test on EV8 and clear it */
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
}

/* Send STOP condition */
I2C_GenerateSTOP(I2C1, ENABLE);
}

/**
* @brief   从EEPROM里面读取一块数据
* @param
*		@arg pBuffer:存放从EEPROM读取的数据的缓冲区指针
*		@arg WriteAddr:接收数据的EEPROM的地址
*     @arg NumByteToWrite:要从EEPROM读取的字节数
* @retval  无
*/
void I2C_EE_BufferRead(u8* pBuffer, u8 ReadAddr, u16 NumByteToRead)
{
//*((u8 *)0x4001080c) |=0x80;
while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY)); // Added by Najoua 27/08/2008

/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
//*((u8 *)0x4001080c) &=~0x80;

/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for write */
I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);

/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

/* Clear EV6 by setting again the PE bit */
I2C_Cmd(I2C1, ENABLE);

/* Send the EEPROM's internal address to write to */
I2C_SendData(I2C1, ReadAddr);

/* Test on EV8 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

/* Send STRAT condition a second time */
I2C_GenerateSTART(I2C1, ENABLE);

/* Test on EV5 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for read */
I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Receiver);

/* Test on EV6 and clear it */
while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

/* While there is data to be read */
while(NumByteToRead)
{
if(NumByteToRead == 1)
{
/* Disable Acknowledgement */
I2C_AcknowledgeConfig(I2C1, DISABLE);

/* Send STOP Condition */
I2C_GenerateSTOP(I2C1, ENABLE);
}

/* Test on EV7 and clear it */
if(I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED))
{
/* Read a byte from the EEPROM */
*pBuffer = I2C_ReceiveData(I2C1);

/* Point to the next location where the byte read will be saved */
pBuffer++;

/* Decrement the read bytes counter */
NumByteToRead--;
}
}

/* Enable Acknowledgement to be ready for another reception */
I2C_AcknowledgeConfig(I2C1, ENABLE);
}

/**
* @brief  Wait for EEPROM Standby state
* @param  无
* @retval 无
*/
void I2C_EE_WaitEepromStandbyState(void)
{
vu16 SR1_Tmp = 0;

do
{
/* Send START condition */
I2C_GenerateSTART(I2C1, ENABLE);
/* Read I2C1 SR1 register */
SR1_Tmp = I2C_ReadRegister(I2C1, I2C_Register_SR1);
/* Send EEPROM address for write */
I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);
}while(!(I2C_ReadRegister(I2C1, I2C_Register_SR1) & 0x0002));

/* Clear AF flag */
I2C_ClearFlag(I2C1, I2C_FLAG_AF);
/* STOP condition */
I2C_GenerateSTOP(I2C1, ENABLE);
}
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