daveb@geaclib.UUCP (David Collier-Brown) (04/02/89)
Well, it looks like for instructions and data with the current technologies, alignment of data makes good sense and architectural support for misaligned accesses is not a good use for silicon. But what about in the communications realm? Current packet formats are rather heavily "packed", sufficiently so that one wants to treat them as collections of bits of various lengths (usually even, often powers of two, etc). Two possibilities arise: Communications will be pushing physical transmission-speed limits and central processors will continue to get faster, faster. With processor time available for unpacking, packets will be densely packed, or Processing speeds will peak out sooner than transmission speeds in the near term, and there will be a need to design communications packet formats so they **aren't** an expanding-opcode scheme. In this scenario I'm not suggesting any holes are likely to appear, but I do expect most of the fields at the beginning of the (outer!) packet will be of fixed size and unchanging interpretation. Would anyone with very-high-speed comms experience care to comment on the ratio of development speeds? And does special-purpose hardware make any sense in this context... --dave -- David Collier-Brown. | yunexus!lethe!dave Interleaf Canada Inc. | 1550 Enterprise Rd. | He's so smart he's dumb. Mississauga, Ontario | --Joyce C-B