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章其波的代码,其中SD卡模块中有一句话,单片机每次都卡在这里不再运行····
while(SPI_WriteByte(0xff) != 0xfe);
我想知道是不是SD卡出了问题,还望各位前辈告知下
原函数:
unsigned char FAT_ReadSector(unsigned long sector, unsigned char* buffer)
{
unsigned char r1;
unsigned int i;
unsigned char retry=0;
r1 = MMC_SD_SendCommand(17, sector<<9);
if(r1 != 0x00)
{
return r1;
}
SPI_CS_Assert();
//等数据的开始
while(SPI_WriteByte(0xff) != 0xfe);//if(retry++ > 50){LCD_write_english_string(0,3,"start2");SPI_CS_Deassert();return 1; }
for(i=0; i<512; i++)//读512个数据
{
*buffer++ = SPI_WriteByte(0xff);
}
SPI_WriteByte(0xff);//伪crc
SPI_WriteByte(0xff);
SPI_CS_Deassert();
return 0;
} |
阿莫论坛20周年了!感谢大家的支持与爱护!!
一只鸟敢站在脆弱的枝条上歇脚,它依仗的不是枝条不会断,而是自己有翅膀,会飞。
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