Identify Frame and RRDY transmission.

Mona monika.talwar at nsysinc.com
Wed Dec 13 23:50:45 PST 2006


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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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