SDHC_TRANSFER_MODE
SDHC_WRITE(sc, SDHC_TRANSFER_MODE, 0x00000000);
HWRITE4(hp, SDHC_TRANSFER_MODE, command << 16);
HWRITE4(hp, SDHC_TRANSFER_MODE, mode | (command << 16));
HWRITE2(hp, SDHC_TRANSFER_MODE, mode);