请教stm32 FSMC读取NAND速度能多快?我测试到只有不到5Mbyte/S
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:void FSMC_NAND_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
FSMC_NANDInitTypeDef FSMC_NANDInitStructure;
FSMC_NAND_PCCARDTimingInitTypeDefp;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE |
RCC_APB2Periph_GPIOF | RCC_APB2Periph_GPIOG, ENABLE);
/*-- GPIO Configuration ------------------------------------------------------*/
/* CLE, ALE, D0->D3, NOE, NWE and NCE2NAND 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);
} 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= *(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);
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);
} 自己对这STM32的手册看了一天了,确实没有找到速度亏在哪里了,CPU时钟72MHz肯定没有问题!刚刚用示波器抓的FSMC_NOE引脚波形:
我去 这么专业赞一个 我连怎么测都不知道。。 刚刚也在Google搜索了一下其他信息。看来FSMC整体速度也就那样了。很多说速度处于5~10MHz(SYSCLK=72MHz)。所以得想起他办法了,要是用STM32+NAND+LCD方案来做LCD显示的话。估计速度更不行了。因为大家都要用FSMC! 这个速度可以了 FMSC驱动屏幕闪屏应该是显示屏的问题,扫描刷新慢。240*320=76800 76800*24(帧)=1843200(速率) =1.8MHz 而FMSC的吞吐速度足够显示视频。 膜拜一下楼主,学习了。
页:
[1]