ISOC_HEADER_DATA_LENGTH_MASK
return (header & ISOC_HEADER_DATA_LENGTH_MASK) >> ISOC_HEADER_DATA_LENGTH_SHIFT;
*header &= ~ISOC_HEADER_DATA_LENGTH_MASK;
*header |= (((u32)data_length) << ISOC_HEADER_DATA_LENGTH_SHIFT) & ISOC_HEADER_DATA_LENGTH_MASK;