I think we have 2 choices in defining a
"PWG profile CDB ",
1st choice:
If we decide to define the PWG profile CDB in a way that there is
a 1284.4 specific CDB content encapsulated in a
"generic CDB frame structure" (generic, meaning supporting various upper
layers) which is intended to support other upper layers as well as 1284.4,
we will need to define 2 things:
1)"generic CDB frame structure"...will include header to distingush
actual content (ex. 1284.4, or other alternative layers)
2)1284.4 specific CDB content ....actual content of CDB which is 1284.4
information
2nd choice:
If we decide that the PWG profile CDB will be 1284.4 specific,
in this case we will only need to define:
1) 1284.4 specific CDB content
In either case,
1284.4 supportive flag and packet header will be included in
1284.4 specific CDB content.
I AGREE that this 1284.4 "short-cut" may be effective
AS LONG AS it is not defined in the "generic structure" but defined in
1284.4
specific content definition.
---
Now, my opinion on making he PWG profile CDB "generic" vs making it
"1284.4 specific".
Since SBP-2 already has a mechanism to distinguish the contents of the CDB
("command_set_spec_id" and "sw_version"), I think we do not need a "CDB
frame"
to do the same thing.
SBP-2 itself is already "generic"
I think the PWG profile should define the CDB to be 1284.4 specific.
P.S. Alan,Nagasaka-san, I apologize if this discussion is already out of
synch.
I have not yet had time to read the updated profile.
Atsushi Nakamura
Canon Inc.
----------
> $B:9=P?M(J : Nagasaka Fumio <Nagasaka.Fumio@exc.epson.co.jp>
> $B08@h(J : 'ALAN_BERKEMA@hp-roseville-om2.om.hp.com'
> CC : 'p1394@pwg.org'
> $B7oL>(J : P1394> RE: [PP1394:00137]
> $BAw?.F|;~(J : 1998$BG/(J1$B7n(J9$BF|(J 16:59
>
> Thank you Alan, for your great effort updating PWG profile document.
>
> Larry wrote: (in "P1394> December Meeting Minutes")
> > H- Section 14, Multiple Logical Channels
> > Routing information needs to be provided here, not .4 Channel
> information.
> $B%j(J => PSID and SSID should be removed from the command_block
>
> At LA meeting, we agreed to remove PSID and SSID from CDB of normal
> command block ORB. However, now I would like to suggest to enclose
> 1284.4 supportive flag and 6 bytes 1284.4 packet header in CDB.
>
> The reason is outlined below.
> 1) IEEE 1284.4 is providing "out-of-band packet control flag" in the
> header
> for 1284.4 packets.
> 2) However if we does not enclose any 1284.4 information in normal
> command
> block ORB. Fetch Agent needs to examine buffered data that wad
> fetched
> after the fetch agent processed the ORB.
> 3) Basically, out-of-band packet shall be extracted as soon as
> possible.
> 4) Thus we would like to make short cut to detect out-of-band requests
> without
> reading buffer space associated with each ORB.
>
> --------------------------------------------
> -------------------------------
> Fumio Nagasaka
> Epson Software Development Laboratory Inc.
> Tel +81 268 25 4111, Fax +81 268 25 4627
> E-mail to nagasaka.fumio@exc.epson.co.jp
>
> -----Original Message-----
> From: ALAN_BERKEMA@hp-roseville-om2.om.hp.com
> [SMTP:ALAN_BERKEMA@hp-roseville-om2.om.hp.com]
> Sent: Friday, January 09, 1998 7:38 AM
> To: pp1394 ML
> Subject: [PP1394:00137]
>
> << File: ccMail >> << File: pwgprof.pdf >>
>