P1394 Mail Archive: Re: P1394> Some question about Command Set Proposal Revision 0d

P1394 Mail Archive: Re: P1394> Some question about Command Set Proposal Revision 0d

Re: P1394> Some question about Command Set Proposal Revision 0d

johnson ho (johnsonh@avance.com)
Fri, 21 Aug 1998 13:48:44 +0800

Hi Robert:
Thanks for your reply. But I still have some problems in question 3. I
am now developping a simple PWG model in the win98 system. One host is as
initiator and another is as target.

If I want to using a TRANSPORT_T2I_DATA command to demand the target to
send a file (unknown size). If the information of the size of memory address
range is got from TRANSPORT_CAPABILITES command. If the size of memory
address range is smaller than file size. The target shall send a Status ORB
with the field of sbp_status is 8 (resource unavailable).But it doesn't make
sense. If I have printer with 4M memory and I want to print 8M's file. The
printer will reject my command. Or is there any way to send this file in
several times into the same memory address range??? It must prevent the
target rewrite the same memory address range before initiator put these data
into buffer or file.

As you say "The initiator transport client (e.g. application layer)
only knows the size of the target's data by pre-arrangement". Does the way
of pre-arrangement show protocol in sbp-2 ???? or it shall get by
self-defined way???

Thanks for your answer of question 1,2. I appended these function in my
application.

May you have a good day.

Johnson Ho

-----原始郵件-----
寄件者: Robert Morford <bob@sismicro.com>
收件者: johnson ho <johnsonh@avance.com>
副本抄送: p1394@pwg.org <p1394@pwg.org>
日期: 1998年8月17日 PM 09:54
主旨: Re: P1394> Some question about Command Set Proposal Revision 0d

>johnson ho wrote:

>> 3.If there are two device, initiator wants target to the send file
>> (command 4). The file size is just known by target. How does initiator
get
>> this information(file size)??? Using Status ORB??? and if the initiator
just
>> want target to write the data on the fixed CSR address range( for
example.
>> FFFF F0011000 ~ FFFF F0012000). But file size is larger than this memory
>> buffer. How should I implement????
>
>The initiator transport client (e.g. application layer) only knows the size
>of the target's data by pre-arrangement. In general, the initiator will
have
>to allocate multiple buffers to the target until all of the data is
transferred.
>Of course, the target may send less than a full buffer by using the
residual
>field in the status block for the corresponding ORB. In essence, the
initiator
>allows T2I transfers by providing ORBs to the target. The target is then
enabled
>to transfer data to the initiator until it runs into one of the limits (ORB
>buffer size, bus reset, task abort ...)
>
>--
>Bob Morford (bob@sismicro.com)
>SIS Microelectronics, Inc.
>A Subsidiary of Aspec Technology, Inc.
>1831 Lefthand Cir., Suite #E
>Longmont, CO 80501
>303-776-1667 x226
>
>