The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Mar 29th, 2024, 6:24am
Pages: 1
Send Topic Print
Looking for study report on 128b/130b coding (Read 4808 times)
neoflash
Community Fellow
*****
Offline

Mixed-Signal
Designer

Posts: 397

Looking for study report on 128b/130b coding
Jul 29th, 2010, 5:45pm
 
Hi,

PCI-E is adopting 128/130 coding to replace 8b/10b encoding.

I'm looking for materials studying the code performance, such as transition density, DC balancing, maximum run length...

Thanks for the sharing of the information.
Neo
Back to top
 
 
View Profile   IP Logged
supermoment
Senior Member
****
Offline



Posts: 167

Re: Looking for study report on 128b/130b coding
Reply #1 - Jul 30th, 2010, 12:40am
 
I think the similar theories of 8B10B may be applied to 128B/130B to achieve dc balance. The 2 preamble bits is used as sync payload.
But the max run length / data density depends on data scrambler.

That means the CDR will be more challenging! It has more DC wander, thus it needs larger CDR bandwidth (around 5-10MHz).
On the other hand to reduce jitter (clk), Tx/Rx PLL bandwidth must be reduced.
Back to top
 
 
View Profile   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2024 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.