此段SD命令子程序程序中是怎么将命令参数写入的
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SD卡操作中的命令写入子程序,小弟C语言不怎么精通,想知道下面程序中(((unsigned char *)&argument)[0])是什么意思怎么用的。 void SdCommand(unsigned char command, unsigned long argument, unsigned char CRC) { SdWrite(command|0x40); SdWrite(((unsigned char *)&argument)[0]); SdWrite(((unsigned char *)&argument)[1]); SdWrite(((unsigned char *)&argument)[2]); SdWrite(((unsigned char *)&argument)[3]); SdWrite(CRC); }
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