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Clause 48: Sync StateMachine and PUDI/invalid/

	I know it is too late for comments on this draft, however I would like
some feedback on this subject:

	The sync state machine uses PUDI/invalid/ to transition through its
states.  The problem I have is that, to calculate PUDI invalid you must
practically decode the code-group.  The decoder is in a different clock
domain on the other side of the lane-align block.  If I use that decoder
to send a signal back to the Sync state machine I have a long round trip
delay for the data to be decoded and send back an error.  Also this does
not conform to the standard since what I am decoding is an AUDI not a
PUDI.  This would also cause LOS of Sync when an internal FIFO error or
Rate Adjustment error could have occured.

I have 2 thoughts on solving this.  
1. Put the decoder next to the Sync StateMachine before the lane align,
and adjust the RCV statemachine accordingly.

2. Use a simplier indicator in the sync statemachine than PUDI/invalid/.
Like just Running Disparity Error.

What do you think?

Justin Gaither                       Phone: 512-306-7292  x529
RocketChips a Division of Xilinx     Fax:   512-306-7293
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Austin, TX 78746               WWW:
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