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eeprom用iic通信。eeprom有几个特点需要关注：
1、可以单字节读写
2、eeprom按页划分存储，不同型号的eeprom的页大小不一致，往eeprom写数据时，如果写到了该页的末尾，会自动从该页的开头继续写，把之前的数据覆盖，读则不会。
/** Copyright 2017 NXP* All rights reserved.** SPDX-License-Identifier: BSD-3-Clause*//* Standard C Included Files */
#include <stdio.h>
#include <string.h>
#include "pin_mux.h"
#include "clock_config.h"
#include "board.h"
#include "fsl_debug_console.h"
#include "fsl_lpi2c.h"/******************************************************************************** Definitions******************************************************************************/
#define EEPROM_I2C_MASTER (LPI2C3)
#define EEPROM_I2C_BAUD (400000UL)/* Select USB1 PLL (480 MHz) as master lpi2c clock source */
#define LPI2C_CLOCK_SOURCE_SELECT (0U)
/* Clock divider for master lpi2c clock source */
#define LPI2C_CLOCK_SOURCE_DIVIDER (5U)
/* Get frequency of lpi2c clock */
#define LPI2C_CLOCK_FREQUENCY ((CLOCK_GetFreq(kCLOCK_Usb1PllClk) / 8) / (LPI2C_CLOCK_SOURCE_DIVIDER + 1U))
#define LPI2C_MASTER_CLOCK_FREQUENCY LPI2C_CLOCK_FREQUENCY#define AT24C256
#define EEPROM_PAGE_SIZE 64
#define EEPROM_SIZE (32*1024)
#define EEPROM_ADDR_BYTES 2
#define EEPROM_WRITE_ADDRESS_8_BIT (0xA2)
#define EEPROM_READ_ADDRESS_8_BIT (0xA3)/******************************************************************************** Prototypes******************************************************************************//******************************************************************************** Variables******************************************************************************//******************************************************************************** code******************************************************************************/
void EepromDelayUs(uint32_t us)
{uint32_t tcnt;tcnt = us * (CLOCK_GetFreq(kCLOCK_CpuClk) / 1000000);while(tcnt--);
}/******************************************************************************** @brief eeprom takes time to write data* @param call after write data to eeprom* @retval
******************************************************************************/
uint8_t EepromWriteWait(uint8_t SlaveAddr8bit)
{status_t reVal = kStatus_Fail;uint32_t delay_count = 1000;do{/* �����Ӧ���־���Ա���һ�μ�� */LPI2C_MasterClearStatusFlags(EEPROM_I2C_MASTER, kLPI2C_MasterNackDetectFlag);/* ��EEPROM����д�����Ѱַ�źţ��Լ���Ƿ���Ӧ */reVal = LPI2C_MasterStart(EEPROM_I2C_MASTER, (SlaveAddr8bit>>1), kLPI2C_Write);/* ����ȴ�����30us���Ż������Ӧ���־*/EepromDelayUs(100);/* ���LPI2C MSR�Ĵ�����NDF��־������ȷ��delay_countû����0������0��Ϊ��ʱ���˳��� */}while(EEPROM_I2C_MASTER->MSR & kLPI2C_MasterNackDetectFlag && delay_count-- );/* �����Ӧ���־����ֹ��һ��ͨѶ���� */LPI2C_MasterClearStatusFlags(EEPROM_I2C_MASTER, kLPI2C_MasterNackDetectFlag);/* ����ֹͣ�źţ���ֹ�´�ͨѶ���� */reVal = LPI2C_MasterStop(EEPROM_I2C_MASTER);/* ����ȴ�����10us��ȷ��ֹͣ�źŷ������*/EepromDelayUs(100);/* ����ʧ�ܻ�ǰ��ĵȴ���ʱ */if(delay_count == 0 || reVal != kStatus_Success){return kStatus_Fail;}return kStatus_Success;
}/*!* @brief I2C Msater Init*/
void I2CMsaterInit(LPI2C_Type *base,uint32_t baud)
{status_t reVal = kStatus_Fail;/*Clock setting for LPI2C*/CLOCK_SetMux(kCLOCK_Lpi2cMux, LPI2C_CLOCK_SOURCE_SELECT);CLOCK_SetDiv(kCLOCK_Lpi2cDiv, LPI2C_CLOCK_SOURCE_DIVIDER);lpi2c_master_config_t masterConfig;/** masterConfig.debugEnable = false;* masterConfig.ignoreAck = false;* masterConfig.pinConfig = kLPI2C_2PinOpenDrain;* masterConfig.baudRate_Hz = 100000U;* masterConfig.busIdleTimeout_ns = 0;* masterConfig.pinLowTimeout_ns = 0;* masterConfig.sdaGlitchFilterWidth_ns = 0;* masterConfig.sclGlitchFilterWidth_ns = 0;*/LPI2C_MasterGetDefaultConfig(&masterConfig);/* Change the default baudrate configuration */masterConfig.baudRate_Hz = baud;/* Initialize the LPI2C master peripheral */LPI2C_MasterInit(base, &masterConfig, LPI2C_MASTER_CLOCK_FREQUENCY);
}/*
subaddressSize is 2
*/
int32_t I2CMsaterWriteData(uint8_t SlaveAddr8bit, uint16_t WriteAddr, uint8_t* pBuffer,uint16_t DataSize)
{int32_t reVal;lpi2c_master_transfer_t masterXfer = {0};masterXfer.slaveAddress = (SlaveAddr8bit>>1);masterXfer.direction = kLPI2C_Write;masterXfer.subaddress = (uint32_t)WriteAddr;masterXfer.subaddressSize = EEPROM_ADDR_BYTES;masterXfer.data = pBuffer;masterXfer.dataSize = DataSize;masterXfer.flags = kLPI2C_TransferDefaultFlag;/* Send master non-blocking data to slave */reVal = LPI2C_MasterTransferBlocking(EEPROM_I2C_MASTER, &masterXfer);if (reVal != kStatus_Success){return -1;}return 0;
}/*
subaddressSize is 2
*/
int32_t I2CMsaterReadData(uint8_t SlaveAddr8bit, uint16_t readAddr, uint8_t* pBuffer,uint16_t DataSize)
{int32_t reVal;lpi2c_master_transfer_t masterXfer = {0};/* start + slaveaddress(w) + subAddress + repeated start + slaveaddress(r) + rx data buffer + stop */masterXfer.slaveAddress = (SlaveAddr8bit>>1);masterXfer.direction = kLPI2C_Read;masterXfer.subaddress = (uint32_t)readAddr;masterXfer.subaddressSize = EEPROM_ADDR_BYTES;masterXfer.data = pBuffer;masterXfer.dataSize = DataSize;masterXfer.flags = kLPI2C_TransferDefaultFlag;reVal = LPI2C_MasterTransferBlocking(EEPROM_I2C_MASTER, &masterXfer);if (reVal != kStatus_Success){return -1;}return 0;
}/*******************************************************************************
when NumByteToWrite > EEPROM_PAGE_SIZE ,it will go back to the start address of the page and write continuely
******************************************************************************/
int32_t EepromWriteData(uint8_t SlaveAddr8bit, uint16_t WriteAddr, uint8_t* pBuffer, uint16_t NumByteToWrite)
{status_t reVal = kStatus_Fail;uint16_t firstPageBytes,otherPageBytes,otherPageNum,lastPageBytes;firstPageBytes = EEPROM_PAGE_SIZE - (WriteAddr % EEPROM_PAGE_SIZE);otherPageBytes = (NumByteToWrite > firstPageBytes) ? (NumByteToWrite - firstPageBytes) : 0;if (otherPageBytes==0){reVal = I2CMsaterWriteData(SlaveAddr8bit, WriteAddr, pBuffer, NumByteToWrite);if (reVal != kStatus_Success){return kStatus_Fail;}EepromWriteWait(SlaveAddr8bit);}else{otherPageNum = otherPageBytes / EEPROM_PAGE_SIZE;lastPageBytes = otherPageBytes % EEPROM_PAGE_SIZE;//write first pagereVal = I2CMsaterWriteData(SlaveAddr8bit, WriteAddr, pBuffer, firstPageBytes);if (reVal != kStatus_Success){return kStatus_Fail;}EepromWriteWait(SlaveAddr8bit);WriteAddr += firstPageBytes;pBuffer += firstPageBytes;if(otherPageNum== 0 ){reVal = I2CMsaterWriteData(SlaveAddr8bit, WriteAddr, pBuffer, lastPageBytes);if (reVal != kStatus_Success){return kStatus_Fail;}EepromWriteWait(SlaveAddr8bit);}else{while(otherPageNum--){reVal = I2CMsaterWriteData(SlaveAddr8bit, WriteAddr, pBuffer, EEPROM_PAGE_SIZE);if (reVal != kStatus_Success){return kStatus_Fail;}EepromWriteWait(SlaveAddr8bit);WriteAddr += EEPROM_PAGE_SIZE;pBuffer += EEPROM_PAGE_SIZE;}if(lastPageBytes != 0){reVal = I2CMsaterWriteData(SlaveAddr8bit, WriteAddr, pBuffer, lastPageBytes);if (reVal != kStatus_Success){return kStatus_Fail;}EepromWriteWait(SlaveAddr8bit);}}}return kStatus_Success;
}#define BUFF_SIZE 255
uint8_t TxBuffer1[BUFF_SIZE];
uint8_t RxBuffer1[BUFF_SIZE];
void EerpromTest(void)
{uint16_t i,cnt;cnt = sizeof(TxBuffer1)/sizeof(TxBuffer1[0]);for(i=0;i<cnt;i++){*(TxBuffer1+i) = i;}//test write 1 pageI2CMsaterWriteData(EEPROM_WRITE_ADDRESS_8_BIT,2,TxBuffer1,cnt);EepromWriteWait(EEPROM_WRITE_ADDRESS_8_BIT);I2CMsaterReadData(EEPROM_READ_ADDRESS_8_BIT,0,RxBuffer1,cnt);//test write more than 1 pageEepromWriteData(EEPROM_WRITE_ADDRESS_8_BIT,0,TxBuffer1,cnt);I2CMsaterReadData(EEPROM_READ_ADDRESS_8_BIT,0,RxBuffer1,cnt);
}