Identify Frame and RRDY transmission.

George Penokie gop at us.ibm.com
Thu Dec 14 15:51:51 PST 2006


Formatted message: <A HREF="r0612144_f.htm">HTML-formatted message</A>

Mona,
1) The wording in 7.16.1 is not a problem as the there is no OPEN_ACCEPT 
sent if an RRDY cannot be sent within 1 ms. That's what the statement "and 
not accept the connection request" means.
An SSP phy that accepts an OPEN address frame shall transmit at least one 
RRDY in that connection within
1 ms of transmitting an OPEN_ACCEPT. If the SSP phy is not able to grant 
credit, it shall respond with
OPEN_REJECT (RETRY) and not accept the connection request.
2) They are approximately the same time, as the point at which the phy 
reset sequence completes is approximately the same as the point at which 
the identify message is sent which is all the overview is attempting to 
accomplish. The precise time at which to start the timer is what is 
defined in the state machine description.
Bye for now,
George Penokie
Dept 9A8 030-3 A410
E-Mail:    gop at us.ibm.com
Internal:  553-5208
External: 507-253-5208
Mona <monika.talwar at nsysinc.com> 
Sent by: owner-t10 at t10.org
12/14/2006 01:50 AM
Please respond to
monika.talwar at nsysinc.com
To
t10 at t10.org
cc
Subject
Identify Frame and RRDY transmission.
Hello all,
I am referring to sas2r07 version. 
1)Please see the section 7.16.1 of the specification.
 7.16.1 Opening an SSP connection
An SSP phy that accepts an OPEN address frame shall transmit at least one 
RRDY in that connection within
1 ms of transmitting an OPEN_ACCEPT. If the SSP phy is not able to grant 
credit, it shall respond with
OPEN_REJECT (RETRY) and not accept the connection request.
According to this statement, OPEN_REJECT will be transmitted if RRDY can't 
b transmitted after accepting the connection. It means OPEN_REJECT(RETRY) 
will be transmitted after OPEN_ACCEPT is transmitted.
But as stated in Table 88, OPEN_REJECT is transmitted when there is no 
connection. Both the statements are in contrary. 
2) The last line of section 7.9.1 Identification and hard reset sequence 
overview states:
(A)   "If a phy does not receive a HARD_RESET primitive sequence or a 
valid IDENTIFY address frame within 1 ms of phy reset sequence completion, 
it shall restart the phy reset sequence."
But 3rd para of section 7.9.4.5.3.1 State description  states:
(B)   "After this state receives an Identify Transmitted message, it shall 
initialize and start the Receive Identify Timeout timer."
Does spec. refer to same timer in both the statements. In case they are 
same (A) asks to start the timer after phy reset sequence is over while 
(B) asks to start the timer after transmitting the Identify Frame. There 
will always be overhead or delays related to Identify frame transmission. 
Which is the correct implementation. Shall the timer be started after 
Frame is transmitted or after phy reset sequence is over.
Please suggest.
Thanks & Best regards
Mona
nSys
http://www.nsysinc.com
Accelerating designs
+1-510-402-4544
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