STM32存储左右互搏 I2C总线读写FRAM MB85RC16

STM32存储左右互搏 I2C总线读写FRAM MB85RC16

在较低容量存储领域，除了EEPROM的使用，还有铁电存储器FRAM的使用，相对于EEPROM, 同样是非易失性存储单元，FRAM支持更高的访问速度， 其主要优点为没有EEPROM持续写操作跨页地址需要变换的要求，没有写之后的延时等待要求。MB85RC16是2K Byte（16K bit）的FRAM，能够按字节进行写入且没有写入等待时间。其管脚功能兼容相应容量的EEPOM：

I2C总线访问的FRAM更大容量的型号还有MB85RC128及MB85RC256等。

这里介绍STM32访问FRAM MB85RC16的例程。采用STM32CUBEIDE开发平台，以STM32F401CCU6芯片为例，通过STM32 I2C硬件电路实现读写操作，通过USB虚拟串口进行控制。

STM32工程配置

首先建立基本工程并设置时钟：

配置硬件I2C接口，STM32F401CCU6的I2C快速模式只支持400KHz速率：

中断不用开：

然后配置USB虚拟串口：

保存并生成初始工程代码：

STM32工程代码

USB虚拟串口的使用参考：STM32 USB VCOM和HID的区别，配置及Echo功能实现（HAL）

这里的测试逻辑比较简单，当USB虚拟串口收到任何数据时，STM32在内部对MB85RC16写入从USB虚拟串口收到的数据，然后再回读出来，通过USB虚拟串口发送出去。

USB接收数据的代码：

static int8_t CDC_Receive_FS(uint8_t* Buf, uint32_t *Len)
{
  /* USER CODE BEGIN 6 */
	extern uint8_t cmd;
	extern uint8_t * RData;
	extern uint32_t RDataLen;

	RData = Buf;
	RDataLen = *Len;
	cmd = 1;

  USBD_CDC_SetRxBuffer(&hUsbDeviceFS, &Buf[0]);
  USBD_CDC_ReceivePacket(&hUsbDeviceFS);
  return (USBD_OK);
  /* USER CODE END 6 */
}

MB85RC16的设备默认访问地址为0xA0， MB85RC16的存储单元地址访问略为特殊，11位地址分为两部分，高位的3位放置于I2C设备默认访问地址的第3~第1位，I2C设备默认访问地址第0位仍然为读写控制位，由于采用硬件I2C控制，库函数自行通过识别调用的是发送还是接收函数对第0位进行发送前设置，因此，不管是调用库函数的I2C写操作还是读操作，提供的地址相同。11位地址的低8位通过在发送设备地址后的作为跟随的第一个字节发送。

完成的main.c文件代码如下：

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2023 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
//Written by Pegasus Yu in 2023
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "usb_device.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <string.h>
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
uint8_t CDC_Transmit_FS(uint8_t* Buf, uint16_t Len);
/* 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 ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c1;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C1_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t cmd=0;          //for status control
uint8_t * RData;        //USB rx data pointer
uint32_t RDataLen;      //USB rx data length
uint8_t * TData;        //USB tx data pointer
uint32_t TDataLen;      //USB tx data length

uint16_t MB85RC16_Access_Addr = 0;   //FRAM MB85RC16 access address (11-bit)

#define MB85RC16_Default_I2C_Addr 0xA0


void MB85RC16_Write(uint32_t addr, uint8_t * data, uint32_t len)
{
	uint8_t MB85RC16_I2C_Addr;

	MB85RC16_I2C_Addr = MB85RC16_Default_I2C_Addr | ((addr>>8)<<1); //high 3-bit access address placed into I2C address

	uint8_t TD[len+1];
	TD[0] = addr & 0x00FF;  //low 8-bit access address placed into I2C first data

	memcpy(TD+1, data, len);
	HAL_I2C_Master_Transmit(&hi2c1, MB85RC16_I2C_Addr, TD, len+1, 2700);  //Write data
}

void MB85RC1M_Read(uint32_t addr, uint8_t * data, uint32_t len)
{
	uint8_t MB85RC16_I2C_Addr;

	MB85RC16_I2C_Addr = MB85RC16_Default_I2C_Addr | ((addr>>8)<<1); //high 3-bit access address placed into I2C address

	uint8_t RA[1];
	RA[0] = addr & 0x00FF;  //low 8-bit access address placed into I2C first data

	HAL_I2C_Master_Transmit(&hi2c1, MB85RC16_I2C_Addr, &RA[0], 1, 2700); //Write address for read
	HAL_I2C_Master_Receive(&hi2c1, MB85RC16_I2C_Addr, data, len, 2700); //Read data

}
/* 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_USB_DEVICE_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	if(cmd==1)
	{
		cmd=0;
		MB85RC16_Access_Addr = 0;  //Set FRAM access address here

		MB85RC16_Write(MB85RC16_Access_Addr, RData, RDataLen);

		TDataLen = RDataLen;
		uint8_t TD[TDataLen];
		TData = TD;
		MB85RC1M_Read(MB85RC16_Access_Addr, TData , TDataLen);

		CDC_Transmit_FS(TData, TDataLen);

	}
    /* USER CODE END WHILE */

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

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 25;
  RCC_OscInitStruct.PLL.PLLN = 336;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief I2C1 Initialization Function
  * @param None
  * @retval None
  */
static void MX_I2C1_Init(void)
{

  /* USER CODE BEGIN I2C1_Init 0 */

  /* USER CODE END I2C1_Init 0 */

  /* USER CODE BEGIN I2C1_Init 1 */

  /* USER CODE END I2C1_Init 1 */
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 400000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C1_Init 2 */

  /* USER CODE END I2C1_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOH_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

STM32范例测试

上述范例的测试效果如下：

STM32例程下载

STM32F401CCU6 I2C总线读写FRAM MB85RC16例程

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