请教stm32 FSMC读取NAND速度能多快？我测试到只有不到5Mbyte/S

chaled · 发表于 2015-1-14 08:48:26

今天在神舟3号开发板上测试STM32F103ZET6使用FSMC来读取NAND flash（HY27UF081G2A）。但是无论如何配置FSMC总线，速度都只能不到5Mbyte/S。我用示波器查看的FSMC_NOE引脚波形。然后我用代码读取2048字节耗时大概500uS(读取前后翻转IO电平)。跟4.5M的速度也比较吻合。具体原理图和代码请参考下图：
原理图.jpg

chaled · 发表于 2015-1-14 08:49:06

void FSMC_NAND_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  FSMC_NANDInitTypeDef FSMC_NANDInitStructure;
  FSMC_NAND_PCCARDTimingInitTypeDef  p;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE |
                     RCC_APB2Periph_GPIOF | RCC_APB2Periph_GPIOG, ENABLE);

/*-- GPIO Configuration ------------------------------------------------------*/
/* CLE, ALE, D0->D3, NOE, NWE and NCE2  NAND pin configuration  */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_14 | GPIO_Pin_15 |
                              GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_4 | GPIO_Pin_5 |
                              GPIO_Pin_7;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

  GPIO_Init(GPIOD, &GPIO_InitStructure);

/* D4->D7 NAND pin configuration  */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10;

  GPIO_Init(GPIOE, &GPIO_InitStructure);

/* NWAIT NAND pin configuration */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;

  GPIO_Init(GPIOD, &GPIO_InitStructure);

/* INT2 NAND pin configuration */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
  GPIO_Init(GPIOG, &GPIO_InitStructure);

  /*-- FSMC Configuration ------------------------------------------------------*/
#if 0
  p.FSMC_SetupTime = 0x1;
  p.FSMC_WaitSetupTime = 0x3;
  p.FSMC_HoldSetupTime = 0x2;
  p.FSMC_HiZSetupTime = 0x1;
#endif
//#if 0
  p.FSMC_SetupTime = 0x1;
      p.FSMC_WaitSetupTime = 0x1;
      p.FSMC_HoldSetupTime = 0x1;
      p.FSMC_HiZSetupTime = 0x1;
//#endif

  FSMC_NANDInitStructure.FSMC_Bank = FSMC_Bank2_NAND;
  //FSMC_NANDInitStructure.FSMC_Waitfeature = FSMC_Waitfeature_Enable;
  FSMC_NANDInitStructure.FSMC_Waitfeature = FSMC_Waitfeature_Disable;
  FSMC_NANDInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_8b;
  //FSMC_NANDInitStructure.FSMC_ECC = FSMC_ECC_Enable;
  FSMC_NANDInitStructure.FSMC_ECC = FSMC_ECC_Disable;
  //FSMC_NANDInitStructure.FSMC_ECCPageSize = FSMC_ECCPageSize_512Bytes;
  // for Hynix HY27UF081G2A
  FSMC_NANDInitStructure.FSMC_ECCPageSize = FSMC_ECCPageSize_2048Bytes;

  FSMC_NANDInitStructure.FSMC_AddressLowMapping = FSMC_AddressLowMapping_Direct;
  FSMC_NANDInitStructure.FSMC_TCLRSetupTime = 0x00;
  FSMC_NANDInitStructure.FSMC_TARSetupTime = 0x00;
  FSMC_NANDInitStructure.FSMC_CommonSpaceTimingStruct = &p;
  FSMC_NANDInitStructure.FSMC_AttributeSpaceTimingStruct = &p;

  FSMC_NANDInit(&FSMC_NANDInitStructure);

  /* FSMC NAND Bank Cmd Test */
  FSMC_NANDCmd(FSMC_Bank2_NAND, ENABLE);
}

chaled · 发表于 2015-1-14 08:49:28

u32 FSMC_NAND_ReadSmallPage(u8 *pBuffer, NAND_ADDRESS Address, u32 NumPageToRead)
{
  u32 index = 0x00, numpageread = 0x00, addressstatus = NAND_VALID_ADDRESS;
  u32 status = NAND_READY, size = 0x00;

  while((NumPageToRead != 0x0) && (addressstatus == NAND_VALID_ADDRESS))
  {
/* Page Read command and page address */
*(vu8 *)(Bank_NAND_ADDR | CMD_AREA) = NAND_CMD_READ_1;

*(vu8 *)(Bank_NAND_ADDR | ADDR_AREA) = 0x00;
*(vu8 *)(Bank_NAND_ADDR | ADDR_AREA) = 0X00;
*(vu8 *)(Bank_NAND_ADDR | ADDR_AREA) = ADDR_1st_CYCLE(ROW_ADDRESS);
*(vu8 *)(Bank_NAND_ADDR | ADDR_AREA) = ADDR_2nd_CYCLE(ROW_ADDRESS);

*(vu8 *)(Bank_NAND_ADDR | CMD_AREA) = NAND_CMD_READ_TRUE;

//
while( GPIO_ReadInputDataBit(GPIOG, GPIO_Pin_6) == 0 );

/* Calculate the size */
size = NAND_PAGE_SIZE + (NAND_PAGE_SIZE * numpageread);
#if 0
/* Get Data into Buffer */
for(; index < size; index++)
{
   pBuffer[index]= *(vu8 *)(Bank_NAND_ADDR | DATA_AREA);
}
#endif
      RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);
      DMA1->IFCR = 0x000FUL;
      DMA1_Channel1->CCR &= ~DMA_CCR1_EN;

      DMA1->IFCR = 0x000FUL;                                                                      /*Clear Flag*/
      DMA1_Channel1->CCR &= ~DMA_CCR1_EN;
      DMA1_Channel1->CNDTR = size;                                                       /*Config LCD Data Transfer*/
      DMA1_Channel1->CPAR  = (u32)(Bank_NAND_ADDR | DATA_AREA);
      DMA1_Channel1->CMAR  = (u32)(&pBuffer[index]);
      DMA1_Channel1->CCR = DMA_CCR2_PL | DMA_CCR1_MEM2MEM | DMA_CCR1_MINC | DMA_CCR1_EN;
      while((DMA1->ISR&DMA_ISR_TCIF1) != DMA_ISR_TCIF1);
      DMA1->IFCR = 0x000FUL;                                                                      /*Clear Flag*/
      DMA1_Channel1->CCR &= ~DMA_CCR1_EN;
numpageread++;

NumPageToRead--;

/* Calculate page address */
addressstatus = FSMC_NAND_AddressIncrement(&Address);
  }

  status = FSMC_NAND_GetStatus();

  return (status | addressstatus);
}