基于HAL库的FMC驱动SRAM(IS62WV51216)

原理图

根据原理图配置cubeMX 的 FMC


配置完后生成hal库代码。FMC接口有A\B\C\D四种控制模式，具体区别可以参考添加链接描述。驱动SRAM只需要选择模式A。


在模式A下，需要关心地址的建立时间和数据的建立时间。cubeMX生成的相关代码在FMC.C文件的Timing结构体中。

/* Timing*/ 
	/*This configuration is at system clock bit 80Mhz*/
  Timing.AddressSetupTime 				= 5;
  Timing.AddressHoldTime 				= 15;				/* Min value, Don't care on SRAM Access mode A */
  Timing.DataSetupTime 					= 3;
  Timing.BusTurnAroundDuration 			= 1;
  Timing.CLKDivision 					= 16;				/* Min value, Don't care on SRAM Access mode A */
  Timing.DataLatency 					= 17;				/* Min value, Don't care on SRAM Access mode A */
  Timing.AccessMode 					= FMC_ACCESS_MODE_A;

在cubeMX中配置的时序在此结构体中。
操作内存我们还需要了解FMC的地址映射如下图



在地址空间0x6000 0000h到9FFF FFFFh间的变量为外部RAM的寻址范围
。在0x6000 0000h到9FFF FFFFh中又分为4个256M大小的4个bank。用于驱动不同的存储器。此项目中我们用的bank1的第3区。外部SRAM的寻址是0x6800 0000~0x6BFF FFFF.
在main.h添加枚举

typedef enum {FAILED = 0, PASSED = 1} TestStatus;

```c
bsp.h
```c
#ifndef BSP_SRAM_H_
#define BSP_SRAM_H_

#include "main.h"

#define SRAM_BANK_ADDR				((uint32_t)0x68000000)

#define BUFFER_SIZE         ((uint32_t)0x0100)
#define WRITE_READ_ADDR     ((uint32_t)0x0800)


static void Fill_Buffer(uint16_t *pBuffer, uint32_t uwBufferLenght, uint16_t uwOffset);
static TestStatus Buffercmp(uint16_t *pBuffer1, uint16_t *pBuffer2, uint16_t BufferLength);
void FMC_SRAM_WriteBuffer(uint8_t* pBuffer,uint32_t WriteAddr,uint32_t n);
void FMC_SRAM_ReadBuffer(uint8_t* pBuffer,uint32_t ReadAddr,uint32_t n);
__IO uint32_t FMC_SRAM_Test(void);

#endif 	

bsp.c

#include "bsp_sram.h"

/**
  * @brief  Fills buffer with user predefined data.
  * @param  pBuffer: pointer on the buffer to fill
  * @param  uwBufferLength: size of the buffer to fill
  * @param  uwOffset: first value to fill on the buffer
  * @retval None
  */
static void Fill_Buffer(uint16_t *pBuffer, uint32_t uwBufferLength, uint16_t uwOffset)
{
  uint16_t tmpIndex = 0;

  /* Put in global buffer different values */
  for (tmpIndex = 0; tmpIndex < uwBufferLength; tmpIndex++)
  {
    pBuffer[tmpIndex] = tmpIndex + uwOffset;
  }
}

/**
  * @brief  Compares two buffers.
  * @param  pBuffer1, pBuffer2: buffers to be compared.
  * @param  BufferLength: buffer's length
  * @retval PASSED: pBuffer identical to pBuffer1
  *         FAILED: pBuffer differs from pBuffer1
  */
static TestStatus Buffercmp(uint16_t *pBuffer1, uint16_t *pBuffer2, uint16_t BufferLength)
{
  while (BufferLength--)
  {
    if (*pBuffer1 != *pBuffer2)
    {
      return FAILED;
    }

    pBuffer1++;
    pBuffer2++;
  }

  return PASSED;
}
/**
  * @brief  Writes n bytes in succession, starting at the specified address.
  * @param  pBuffer: pointer on the buffer to load
  * @param  WriteAddr: The address to write 
  */
void FMC_SRAM_WriteBuffer(uint8_t* pBuffer,uint32_t WriteAddr,uint32_t n)
{
	for(;n!=0;n--)  
	{										    
		*(__IO uint8_t*)(SRAM_BANK_ADDR+WriteAddr)=*pBuffer;	  
		WriteAddr++;
		pBuffer++;
	}   
}																			    
/**
  * @brief  Reading n bytes in succession, starting at the specified address.
  * @param  pBuffer: pointer on the buffer to fill
  * @param  ReadAddr: The address to read 
	* @param  n:Length of reading
  */
void FMC_SRAM_ReadBuffer(uint8_t* pBuffer,uint32_t ReadAddr,uint32_t n)
{
	for(;n!=0;n--)  
	{											    
		*pBuffer++=*(__IO uint8_t*)(SRAM_BANK_ADDR+ReadAddr);    
		ReadAddr++;
	}  
} 

__IO uint32_t FMC_SRAM_Test(void)
{
	uint32_t uwIndex = 0;
	__IO uint32_t uwWriteReadStatus = 0;
	
	uint16_t aTxBuffer[BUFFER_SIZE];
	uint16_t aRxBuffer[BUFFER_SIZE];
	 
	Fill_Buffer(aTxBuffer, BUFFER_SIZE, 0xC20F);
	
	/* Write data to the SRAM memory */
  for(uwIndex = 0; uwIndex < BUFFER_SIZE; uwIndex++)
  {
    *(__IO uint16_t *)(SRAM_BANK_ADDR + WRITE_READ_ADDR + 2 * uwIndex) = aTxBuffer[uwIndex];
  }
	
	/* Read back data from the SRAM memory */
  for(uwIndex = 0; uwIndex < BUFFER_SIZE; uwIndex++)
  {
    aRxBuffer[uwIndex] = *(__IO uint16_t *)(SRAM_BANK_ADDR + WRITE_READ_ADDR + 2 * uwIndex);
  }
	
	/*##-3- Checking data integrity ############################################*/
  uwWriteReadStatus = Buffercmp(aTxBuffer, aRxBuffer, BUFFER_SIZE);
	return uwWriteReadStatus;
}

此项目的硬件平台为STM32L471ZE