P1394 Mail Archive: RE: P1394> 1212 Issues - was May 1394 PWG Definitions

P1394 Mail Archive: RE: P1394> 1212 Issues - was May 1394 PWG Definitions

RE: P1394> 1212 Issues - was May 1394 PWG Definitions

Turner, Randy (rturner@sharplabs.com)
Wed, 27 May 1998 17:20:50 -0700

See my comments below...


-----Original Message-----
From: Greg LeClair [SMTP:gleclair@agentz.com]
Sent: Wednesday, May 27, 1998 4:34 PM
To: p1394@pwg.org
Subject: P1394> 1212 Issues - was May 1394 PWG

Others that have been involved in revisions work please

My understanding is that current 1212 definitions are an issue.
See if the following applies:

Changes to Config ROM may be limited to new keys and or
Is this what you meant by "revise how config ROM is structured"?

Yes. But limiting changes to "structures" is not very limiting.
Our original proposal including the addition of a "function" directory
is just such a structure addition.

And yes, there is legacy within 1212. The existing spec, it's
inclusion as
a reference in other specs and bus standards......

I was referring to "legacy" in the case of "legacy" SBP-2
implementations in shipping devices that would be used as "targets".

I think 1212R is just extending 1212 to cover other requirements that
have come up since original publication. Whatever "R" does should be
backwards compatible with the original 1212. Of course, I may be wrong
about this.

The compliance terminology on new items is an issue.


-----Original Message-----
From: Jeff Schnitzer [SMTP:jds@underscore.com]
Sent: Wednesday, May 27, 1998 6:34 AM
To: p1394@pwg.org
Subject: RE: P1394> May 1394 PWG Definitions

From: "Turner, Randy" <rturner@sharplabs.com>
To: "'p1394@pwg.org'" <p1394@pwg.org>
Subject: RE: P1394> May 1394 PWG Definitions
Date: Tue, 26 May 1998 10:29:44 -0700

I was assuming that "current 1212 definitions" would not be an
and that p1212r would take our requirements into account and
revise how
config ROM is structured? With the almost non-existent 1394
base, I'm also assuming there are no legacy 1212 issues do deal


-----Original Message-----
From: Greg Shue [SMTP:gregs@sdd.hp.com]
Sent: Tuesday, May 26, 1998 10:11 AM
To: atsnaka@bsd.canon.co.jp
Cc: p1394@pwg.org
Subject: Re: P1394> May 1394 PWG Definitions

Ats wrote:
> I do not intend to take this up as a problem, but I
feel 1394 protocols
> (current actual usage) do not equate units with
functions, but as
> protocols. (ex. AV/C unit, SBP-2 unit, etc.)
> Under this circumstances and understanding, equating
units to drivers seemed
> to fit.

The big struggle I have with current 1212 definitions is
they do equate *_SW_VERSION with a monolithic driver
(where *
could be either Module, Node, or Unit), and they don't
provide a
way of encoding arbitrary number of layers of drivers
into the
Config ROM. Under this idea, all other layers would
have to
be queried using the identified driver. And this makes
when we remember that 1212 is a Control and Status
Architecture. Now we're trying to encode things well
the register layer. :-)

> Greg said :
> >I think we need to expand the idea of function : unit
on a 1:1 ratio
> True. Another point is
> 1) function : unit on a 1:n ratio......1 function
using/supported by one or more protocols
> (unit dir level)
> 2) function : unit on a n:1 ratio......one or more
functions supported by 1 protocol.
> (unit dir level)
> Though the PWG profile may allow only 1), both have
to be allowed
> looking from the point of 1212 (and any protocols).

We may also need to look at the problem of how to encode
layers of protocols needed to access a function.

Greg Shue
Hewlett-Packard Company
Office Products Division