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RE: Clause 48: enable_cdet

Title: Clause 48: enable_cdet
Enable_cdet is only required to be true to exit the LOSS_OF_SYNC state. It's state is not relevant to progress in any other state of the Synchronization state diagram.
Whenever enable_cdet=TRUE code-group alignment takes occurs. It is undesirable to detect commas aligned to a different boundary once the first comma is detected following entry into the LOSS_OF_SYNC state (and the setting of enable_cdet<=TRUE). Therefore, it is appropriate to disable further code-group alignment upon entry to state COMMA_DETECT_1.


Best Regards,
Richard Taborek Sr.     XAUI Sherpa     Intel Corporation   
Santa Clara Design Center     Network Components Division
408-496-3423     Fax: 408-486-9859     Cell: 408-832-3957
3101 Jay Street, Suite 110          Santa Clara, CA 95054
-----Original Message-----
From: Rogers, Shawn [mailto:s-rogers@xxxxxx]
Sent: Monday, March 26, 2001 2:10 PM
To: 'rich.taborek@xxxxxxxxx'
Cc: '802.3ae'
Subject: Clause 48: enable_cdet

Rich, I'd like some clarification on this before deciding on whether to enter a comment on D2.3. 

In Figure 48.8,
   In the LOSS_OF_SYNC state, enable_cdet = true.
   Exiting LOSS_OF_SYNC state is dependent on valid signal detect and detecting a comma. 
   In the COMMA_DETECT_1 state, enable_cdet = false.
   Exiting COMMA_DETECT_1 to go to COMMA_DETECT_2 is dependent on a valid comma. 

How do you get to COMMA_DETECT_2 when comma detect is turned off?  

Also, on a more generic note, why turn off comma detect so early in the sync state machine?


Shawn Rogers,   PMP
Serial Gigabit Products Dev. Mgr.
Texas Instruments/ 12500 TI Boulevard
M/S 8732/ Dallas, Texas 75243
Tel: 214-480-2678, Fax: 214 761-6954 Pager: 972-597-1803