Table 32 & flow control

Bill Galloway BillG at breatech.com
Wed Nov 15 09:40:10 PST 2000


* From the T10 Reflector (t10 at t10.org), posted by:
* "Bill Galloway" <BillG at breatech.com>
*
Sriram,

I said before that it was discussed in the SPI working group when we were
discussing 00-343r1.  I did not rev my document to include this discussion
and the editor did not include it in rev 1.

I will write a new proposal to copy the ATN setup times into the flow
control setup times for all of the slower DT speeds.  I will also propose
using the same values for the flow control hold times.

No one is trying to prohibit streaming at other than fast-160 speeds.


Bill Galloway
BREA Technologies, Inc.
P: (281) 530-3063
F: (281) 988-0358
BillG at breatech.com

-----Original Message-----
From: Sriram Srinivasan [mailto:srirams at lsil.com]
Sent: Wednesday, November 15, 2000 10:47 AM
To: t10 at t10.org; BillG at breatech.com
Subject: RE: Table 32 & flow control


Bill:

   If ATN timings are used why aren't these used for all transfer rates?
 There is only one entry corresponding to fast-160?  The rest are all
"N/A" NOT EVEN "TBD"!  Does this mean streaming is NOT permitted for
speeds other than fast-160?

   Sections 4.9.3.2 and 4.9.3.3 specify the rates at which data group
and IU transfers are allowed.  But section 4.9.3.3 fails to do the same
with streaming as it does not tie it to any transfer rate, but table 32
does!!!  I believe that there is no other place in the document where it
specifies what transfer rates streaming can happen in.

   Also, paragraph #1 of 4.9.3.2 and 4.9.3.3 are inconsistent w/ table 1
which has a "NO" against DT for Fast-5 transfer rates.

   \Sriram\

~
~ Sriram,
~
~ For 1) the discussion in the meeting was to use the ATN setup times
but that
~ does not answer the question for hold times.  I will look at that some
more.
~
~ For 2) The flow control setup (9.2.12 and 9.2.14) time is specified
for
~ assertion AND negation to handle the case when the next REQ occurs in
~ DT_DATA phase. If you go MSG_IN then the P_CRCA line is the parity for
~ DB[7:0] and you have to meet the flow control hold and the parity
setup.  If
~ you go bus free then you have to meet the flow control hold and all of
the
~ rules for bus free.
~
~
~ Bill Galloway
~ BREA Technologies, Inc.
~ P: (281) 530-3063
~ F: (281) 988-0358
~ BillG at breatech.com
~
~ -----Original Message-----
~ From: owner-t10 at t10.org [mailto:owner-t10 at t10.org]On Behalf Of Sriram
~ Srinivasan
~ Sent: Monday, November 13, 2000 1:33 PM
~ To: t10 at t10.org
~ Subject: Table 32 & flow control
~
~
~ * From the T10 Reflector (t10 at t10.org), posted by:
~ * Sriram Srinivasan <srirams at lsil.com>
~ *
~    I have a couple of questions reg. streaming (all references are to
~ SPI4- rev1):
~
~    1) Table 32 does NOT specify the flow control setup and hold times
~       for speeds other than Fast-160.  It does not even say TBD, it
says
~       N/A.  Isn't streaming associated with just the idea of IU
~       transfers?  Or is it ONLY valid for paced, fast-160 transfers?!?
~
~    2) Section 14.3.4 only talks about how to signal the end of a
stream
~       by asserting the P_CRCA signal.  It does NOT say WHEN the signal
~       has to be negated.  The definition of the flow control setup and
~       hold timings in sections 9.2.11 through 9.2.14 further makes it
~       confusing as it somehow implies that a SPI L_Q follows after
~       a stream ends.  Why should these definitions specify the timing
~       requirement of P_CRCA negation w.r.t REQ assertion for a SPI L_Q
~       IU?  What if the target does a BUS FREE or MESSAGE IN after the
~       end of the stream?  When does the P_CRCA have to be negated in
~       that case?
~
~       Please clarify.
~
~       Thanx,
~       \Sriram\
~
~
~ ----------------------------------------------------------------------
~
~  Sriram Srinivasan                       Sriram.Srinivasan at lsil.com
~  ASIC Design Engineer, LSI Logic,
~  2001 Danfield Ct., 				Phone: 970-206-5847
~  Fort Collins, CO 80525				FAX  :
970-206-5244
~ ----------------------------------------------------------------------
~
~ *
~ * For T10 Reflector information, send a message with
~ * 'info t10' (no quotes) in the message body to majordomo at t10.org
~
~



----------------------------------------------------------------------
	"FORGET NOT THAT THE EARTH DELIGHTS TO FEEL YOUR BARE FEET,
               AND THE WINDS LONG TO PLAY WITH YOUR HAIR"
                                          -Khalil Gibran

 Sriram Srinivasan                       Sriram.Srinivasan at lsil.com
 ASIC Design Engineer, LSI Logic,
 2001 Danfield Ct., 				Phone: 970-206-5847
 Fort Collins, CO 80525				FAX  : 970-206-5244
----------------------------------------------------------------------

*
* For T10 Reflector information, send a message with
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