SD卡的读取

feibosu

if((blksize>0)&&(blksize<=2048)&&((blksize&(blksize-1))==0))
{
  power=convert_from_bytes_to_power_of_two(blksize);     

  SDIO_CmdInitStructure.SDIO_Argument =  blksize;
    SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_SET_BLOCKLEN;
    SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short;
    SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;
    SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;
    SDIO_SendCommand(&SDIO_CmdInitStructure);//·&cent;&Euml;&Iacute;CMD16+&Eacute;è&Ouml;&Atilde;&Ecirc;&yacute;&frac34;&Yacute;&sup3;¤&para;&Egrave;&Icirc;&ordf;blksize,&para;&Igrave;&Iuml;ì&Oacute;&brvbar;

原子的战舰的程序中我为什么要进行blksize的大小的限制呀！为什么blksize的大小要小于2048和)&&((blksize&(blksize-1))==0这个呢？