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ST官方的部分程序是如下:
/* Byte 6 */
tmp = (u8)((CSD_Tab[1] & 0x0000FF00) >> 8);
cardinfo->SD_csd.PartBlockRead = (tmp & 0x80) >> 7;
cardinfo->SD_csd.WrBlockMisalign = (tmp & 0x40) >> 6;
cardinfo->SD_csd.RdBlockMisalign = (tmp & 0x20) >> 5;
cardinfo->SD_csd.DSRImpl = (tmp & 0x10) >> 4;
cardinfo->SD_csd.Reserved2 = 0; /* Reserved */
cardinfo->SD_csd.DeviceSize = (tmp & 0x03) << 10;
/* Byte 7 */
tmp = (u8)(CSD_Tab[1] & 0x000000FF);
cardinfo->SD_csd.DeviceSize |= (tmp) << 2;
/* Byte 8 */
tmp = (u8)((CSD_Tab[2] & 0xFF000000) >> 24);
cardinfo->SD_csd.DeviceSize |= (tmp & 0xC0) >> 6;
cardinfo->SD_csd.MaxRdCurrentVDDMin = (tmp & 0x38) >> 3;
cardinfo->SD_csd.MaxRdCurrentVDDMax = (tmp & 0x07);
搞不懂这三条红色标出的语句。
