P1394 Mail Archive: Re: P1394> Rough SBP-2 & IP1394 core component ROM sizes

Re: P1394> Rough SBP-2 & IP1394 core component ROM sizes

Greg Shue (gregs@sdd.hp.com)
Wed, 11 Feb 1998 08:59:39 -0800 (PST)

Some chipsets offer HW assist for portions of the SBP-2 target
protocol. Others offer HW support for DMA to map device memory
to Serial Bus memory, which significantly improves SBP-2 intiator
performance (e.g. OHCI). This does _not_ mean that the chips
are protocol-specific.

I definitely agree that initiator and target functionality are
vastly different. In my mind, the represent opposite ends of a
client-server model. I think it would be extremely difficult to
write a single application that could, in a single instance (or
through a single interface) be both a controller and a controlled
function. (Note, I did not call this a Module, a Node, or a
device. :-) I could very easily see a protocol stack for a node
having both target and initiator support. Any server-type
services would use the target support. Any client-type
applications would use the initiator support. Because there is
so little that is shared, I see the size of the stacks as being
(roughly) the sum of the individual solutions, no matter how many
applications or services my node has.

Am I missing something here?

Greg Shue

>
>
>
> I didn't know chip sets offered "explicit" support for SBP-2. OHCI
> maybe, but I hadn't seen the chip set feature in the brochure for
> "chip-level SBP-2 support".
>
> Also, since 1394 is a peer-to-peer interface, anyone developing a
> peer-to-peer device (like the majority of the Japanese electronics
> industry), would have to essentially duplicate the functionality of
> SBP-2 initiator and target, whether they actually use SBP-2 to do this,
> or some other (potentially proprietary) method for implementing
> peer-to-peer functionality.
>
> Randy
>
>
>
> -----Original Message-----
> From: Stephen Holmstead [SMTP:stephen@hpb16977.boi.hp.com]
> Sent: Wednesday, February 11, 1998 8:30 AM
> To: 'Turner, Randy'; 'Brian Batchelder'; p1394@pwg.org
> Subject: RE: P1394> Rough SBP-2 & IP1394 core component
> ROM sizes
>
> My experiences in the past is that combining target AND
> initiator
> functions into a single device is VERY difficult. The
> complexity of the
> state tables and ambiguities that can arise make it very
> difficult.
> Also, I don't believe any of the chip manufacturers support
> SBP-2 for
> both target and initiator. In my opinion, it's NOT just a
> matter of
> adding the 15K for the target and 15K for the initiator. The
> target and
> initiator have vastly different functions. Designing a model
> that did
> both (well) would be a challenge. It was problems like this
> that fueled
> many of the AEN (asynchronous event notification) debates.
>
> Stephen
>
> > -----Original Message-----
> > From: Turner, Randy [SMTP:rturner@sharplabs.com]
> > Sent: Monday, February 09, 1998 1:03 PM
> > To: 'Brian Batchelder'; p1394@pwg.org
> > Subject: RE: P1394> Rough SBP-2 & IP1394 core component
> ROM sizes
> >
> >
> > I am very interested in the combined target/initiator
> footprint as
> > well.
> >
> > Thx
> >
> > Randy
> >
> >
> > -----Original Message-----
> > From: Brian Batchelder [SMTP:brianb@vcd.hp.com]
> > Sent: Monday, February 09, 1998 9:37 AM
> > To: p1394@pwg.org
> > Subject: Re: P1394> Rough SBP-2 & IP1394 core
> component
> > ROM sizes
> >
> > At 02:04 PM 2/6/98 -0800, Greg Shue wrote:
> >
> > [snip]
> >
> > >I approached them about sharing some rough estimates of
> code
> > size
> > >for the IP1394 glue, SBP-2 target and initiator, and
> 1394 bus
> > >manager modules to get a feel for how "heavy" the
> protocol
> > >implementations really are. They graciously shared the
> flowing
> > >estimates with us, and certainly deserve our thanks.
> Since the
> > >technology is still being developed, these
> implementations are
> > >certainly going to be tuned and the numbers will change
> a
> > little
> > >bit.
> > >
> > > Component Rough ROM size (KBytes)
> > > --------- -----------------------
> > > SBP-2 initiator core 15 +/- 5
> > > SBP-2 target core 15 +/- 5 (incl. Mgmt+Fetch
> agent,
> > no exec agent)
> >
> > Any idea how big a combined SBP-2 target/initiator would
> be?
> > 15-30K? ;-)
> >
> > [snip]
> >
> > Brian
> >
> >
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > ~
> > Brian Batchelder | Hewlett-Packard |
> > mailto:brianb@vcd.hp.com
> > Connectivity Futurist | 1115 SE 164th Ave. | Phone:
> (360)
> > 212-4107
> > DeskJet Printers | Vancouver, WA 98684 | Fax:
> (360)
> > 212-4227
>

Our website uses cookies on your device to give you the best user experience. By using our website, you agree to the placement of these cookies. To learn more, read our privacy policy. Read Privacy Policy