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Megabit Eye Diagram Measurements in Under a Minute

Posted February 3rd, 2009 · 3 Comments · Conference, Puzzle

Live from DesignCon, Santa Clara

Despite the economy, attendance at DesignCon is quite good. There’s quite a buzz in the air. Key note speaker Walden Rhines, CEO of Mentor Graphics, gave an upbeat prespective in his Keynote Address on the long term trends for EDA producers and consumers.

Today we introduced our ADS million-bit-per-minute Channel Simulator for signal integrity. With a throughput that’s a thousand times faster than SPICE, it is now practical to make changes to the channel or the transmit-and-receive equalization and see eye measurement results instantaneously, enabling “what if” design space exploration.

The Channel Simulator, and its companion Eye Probe is unique because, unlike a point tool, it’s fully integrated into ADS, extracting a fast channel model from any ADS schematic or layout, allowing our you to build the model from regular ADS circuit- and physical-level components. You can access tuning, optimization and batch mode — all from an intuitive user interface.

Agilent ADS Channel Simulator schematic and results

My colleague Sanjeev Gupta used this new Channel Simulator to formulate — and solve — the "open the eye" puzzle contest we ran a while back.

As a reminder, here’s the "before" picture:

Puzzle Event 1 Eye, No Equalization

And here’s the optimum solution:

8.24 dB de-emphasis (2 Tap FIR) on the transmit signal to get maximum normalized eye height and eye width of 140 psec. The eye diagram and the coefficients are shown below. It is an optimal solution utilizing minimum number of taps.

Solution to the eye diagram puzzle contest

The data sheet for the product that includes the Channel Simulator is here:
W2302 Advanced Design System Transient Convolution Element and W2500 Transient Convolution GT Option
And the product page is here:
W2302 Transient Convolution Element
You can download ADS 2009 from:
If you need an evaluation license, please go to:

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