C_BIT
fis[0] = ((nblk & 0xff) << 24) | (C_BIT << 8) | FIS_REG_H2DEV;
fis[0] = (C_BIT << 8) | FIS_REG_H2DEV;
msg[5] = LE_32((READ_LOG_EXT << 16) | (C_BIT << 8) | FIS_REG_H2DEV);