qujian112:
SD卡开发单片机读写SD卡模拟SPI总线的子程序模拟SPI总线的子程序:sbitCS=P1^0;sbitCLK=P1^1;sbitDATaI=P1^2;sbitDATaO=P1^3;#defineSD_Disable()CS=1//DisableCS#defineSD_Enable()CS=0//EnableCSunsignedcharSPI_TransferByte(unsignedcharval){ unsignedcharBitCounter; for(BitCounter=8;BiCounter!=0;BitCounter--) { CLK=0;DATaI=0;//write if(val&0x80)DATaI=1; val