Table 32 & flow control

Bill Galloway BillG at breatech.com
Mon Nov 13 13:12:52 PST 2000


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

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