Table 32 & flow control

Sriram Srinivasan srirams at lsil.com
Wed Nov 15 08:47:12 PST 2000


* From the T10 Reflector (t10 at t10.org), posted by:
* Sriram Srinivasan <srirams at lsil.com>
*
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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