>From consumer device point of view, "symmetrical" is the essential
feature of the protocol.
For example, a digital still camera wants to send its image data to
printers. Also the same camera wants to receive image data from the
other still cameras. We want to use the same protocol for both use.
These are three essential features for consumer device.
1) Bi-directional
Each side can send and receive data.
SBP2 supports bi-directional feature.
2) "True" bi-directional
Each side can send and receive data at any time.
Alan's architecture supports "true" bi-directional feature by using
transmit buffer, receive buffer and unsolicited status.
3) Symmetrical
Each side has the same architecture.
This is completely different from bi-directional issue.
Consumer device needs these three features and the protocol must be
simple.
If SBP2 implementation needs 30K for initiator and target, it might be
difficult to use it for consumer device.
Toru Ueda
Software labs.
Sharp Corp.
On Wed, 11 Feb 1998 08:35:10 -0800
"Turner, Randy" <rturner@sharplabs.com> wrote:
>
>
> 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 Homestead [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
>