使用SDIO+DMA 来读写SD卡，怎么提高写的速度？

elimbug · 发表于 2016-11-7 11:54:27

在MINI开发板上我开始使用SPI接口实现一个读卡器，在Windows上写的速度是200KB左右，满足不了要求。后来我改成使用SDIO接口+DMA的方式来读写SD卡，但是在Windows上写文件的速度只有250KB左右，速度提高不明显啊。我使用的是库函数版本是3.5的。请求指导一下，怎么提高U盘的读写速度啊？？？
另外，如果我想使用外接USB的高速PHY芯片,如USB3300 芯片，是不是只能使用STM32F2或者STM32F4的主控啊？

elimbug · 发表于 2016-11-7 11:54:28

夏至硬汉发表于 2016-11-9 13:04
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&SDIO->DR;求问楼主这个你是怎么配置的，我编译就 ...

我是配置成这样：
#define SDIO_FIFO_Address ((uint32_t)0x40018080)
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)SDIO_FIFO_Address;

elimbug · 发表于 2016-11-9 11:57:57

我自己来顶一下，我测试了一下SPI+SD方式的读写速度，写200KB左右，读350KB左右，是不是我们底层驱动函数导致读写这么慢啊？

elimbug · 发表于 2016-11-9 12:01:34

这是我测试读写速度的程序：
[mw_shl_code=c,true]printf("Write single sector time begin ...\r\n");
couter_time = 0;
TIM_Cmd(TIM3, ENABLE);
for(i=0; i<10000; i++)
{
SDCARD_Write_Sector(read_write_buf,1000+i,1);
}
TIM_Cmd(TIM3, DISABLE);
printf("Write single sector time over ...\r\n");
printf("write single: time=%d s \r\n",couter_time);
printf("write single: speed=%d KBps \r\n",5120/couter_time);//(512 * 1000/1024)=5120

printf("Read single sector time begin ...\r\n");
couter_time = 0;
TIM_Cmd(TIM3, ENABLE);
for(i=0; i<10000; i++)
{
SDCARD_Read_Sector(read_write_buf,1000+i,1);
}
TIM_Cmd(TIM3, DISABLE);
printf("Read single sector time over ...\r\n");
printf("Read single : time=%d s \r\n",couter_time);
printf("Read single : speed=%d KBps \r\n",5120/couter_time);//(512 * 1000/1024)=5120

printf("Write multi sector time begin ...\r\n");
couter_time = 0;
TIM_Cmd(TIM3, ENABLE);
for(i=0; i<10000; i+=20)
{
while( SDCARD_Write_Sector(read_write_buf,20000+i,20) == 0xff){};
}
TIM_Cmd(TIM3, DISABLE);
printf("Write multi sector time over ...\r\n");
printf("write multi: time=%d s \r\n",couter_time);
printf("write multi: speed=%d KBps \r\n",5120/couter_time);//(512 * 1000/1024)=5120

printf("Read multi sector time begin ...\r\n");
couter_time = 0;
TIM_Cmd(TIM3, ENABLE);
for(i=0; i<10000; i+=20)
{
while( SDCARD_Read_Sector(read_write_buf,20000+i,20) == 0xff ){};
}
TIM_Cmd(TIM3, DISABLE);
printf("Read multi sector time over ...\r\n");
printf("Read multi : time=%d s \r\n",couter_time);
printf("Read multi : speed=%d KBps \r\n",5120/couter_time);//(512 * 1000/1024)=5120[/mw_shl_code]