Design Con 2015
Breaking News
Comments
Newest First | Oldest First | Threaded View
michal.kubicek
User Rank
Rookie
Oversampling CDR
michal.kubicek   10/11/2013 2:57:50 AM
We did some FPGA-based research and implementation of oversampling CDR in FPGAs few years ago. The target application was a special device for a local company. We successfully used Cyclone-II as a 4-channel transceiver in this application and later implemented the same algorithms into another product based on Spartan-3 FPGA.

The algorithms were initially based on Xilinx xapp224 but we had to improve them to get reliable data recovery (at the end with very little hardware overhead). With the improvement we were able to compete with traditional PLL-based CDRs. During the research we evaluated FPGA transceivers in oversampling mode as well, see this paper: http://www.radioeng.cz/fulltexts/2010/10_01_074_078.pdf

Our conclusion is that it is efficient and reliable to use oversampling data recovery. The asynchronous (blind) oversampling data recovery is extremely efficient in multichannel (multilane) application, as you need only single clock management block (eg. PLL), which even need not to be synchronized to the data. However, the limiting factor of today FPGAs is the sampler itself - if you use general purpose IOs. Naturally, In ASIC this is not an issue.

Our evaluation of FPGA transceivers (Virtex-5 GTP) was only shallow. The oversampling feature is actually supported in the transceiver core wizard so it was very straightforward to implement it, as the data recovery engine is already part of the IP. The results were somewhat worse than we expected, which might be caused by a poor data extraction algorithm. However, we did not try to fix it by using our data recovery engine implemented within FPGA.

Feel free to email me: kubicek@feec.vutbr.cz



Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

Feast Your Orbs on My Vetinari Clock Prototype
Max Maxfield
10 comments
Well, I have to admit that I have a great big Cheshire Cat-type grin plastered on my face at the moment, because the prototype for my Vetinari Clock project is now well underway.

Jack Ganssle, Embedded.com

Open Office: Your Fart is My Problem
Jack Ganssle, Embedded.com
9 comments
A Washington Post article, Google got it wrong. The open-office trend is destroying the workplace, describes how the author's ad agency moved her from a private office to an open space ...

latest comment bnowak0 Who farted?
Rich Quinnell

Bloopers Book Helps Improve GUI Development
Rich Quinnell
2 comments
Courtesy of fellow editor "Max" Maxfield (aka Max the Magnificent), I recently acquired a copy of GUI Bloopers 2.0 by Jeff Johnson of UI Wizards. I found it an interesting read chock full ...

Rich Quinnell

Making the Grade in Industrial Design
Rich Quinnell
16 comments
As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

Special Video Section
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...
Why culture makes Linear Tech a winner.
Recently formed Architects of Modern Power consortium ...
Specially modified Corvette C7 Stingray responds to ex Indy ...
Avago’s ACPL-K30T is the first solid-state driver qualified ...
NXP launches its line of multi-gate, multifunction, ...
Doug Bailey, VP of marketing at Power Integrations, gives a ...
See how to ease software bring-up with DesignWare IP ...
DesignWare IP Prototyping Kits enable fast software ...
This video explores the LT3086, a new member of our LDO+ ...
In today’s modern electronic systems, the need for power ...