Have you ever plotted an eye diagram in Virtuoso Visualization and Analysis XL and wished that you could overlay an industry standard eye mask to see if your diagram is compliant? Well, now you can! The new tab, Eye Mask, in the Eye Diagram assistant helps you apply a mask from the following industry standards:
- HDMI Compliance
- HDMI 2.0 TP2EQ (Data Rate 3.4G to 3.712G)
- HDMI 2.0 TP2EQ (Data Rate 5.9G to 6G)
- MIPI M-PHY Rx Compliance
- MIPI M-PHY Tx Compliance
- PCI Express Gen 3 Compliance
- SFP+PCB Compliance
If you wish, you can also create your own custom mask that can be saved and used again, or shared with other users.
To check if your eye diagram meets a compliance check, all you need to do is plot a centered eye diagram. Then, simply open the Eye Mask tab on the Eye Diagram assistant, select the eye diagram, then choose the eye mask from the drop-down.
Press Evaluate and see if your eye diagram passes or fails. A passing mask is shown in green and a failing mask is shown in red.
The figures below show the examples of passing and failing eye masks.
Using Mask Expressions on ADE Outputs
You can send these eye mask expressions back to ADE by choosing Send to ADE - Plot Expression, which sends back the expression to plot the eye and mask. Select Test Expression to send back an expression to check if the mask violates or not. You can even add specs to these expressions to see if they pass or fail without having to open Virtuoso Visualization and Analysis XL.
Passing masks have 0 parts touching the mask, so adding a spec of <1 enables you to see this at a glance.
Custom Masks
Creating a custom mask is simple too, just select the eye and then specify a name for your new mask in the drop down, choose the geometry for your mask from the drop down selection of Rectangular, Diamond or Hexagonal.
Then double click on the green points to change the coordinates of the mask. The coordinates for the X-axis are shown in either Unit Intervals (UI) or seconds (s), the Y axis is only seconds (s) - just ensure you select the relevant one before editing the green points.
So, you can see how simple it is to check whether your eye diagram meets some standard compliance checks.
If you would like to watch these steps in detail, you can view the ViVA-Using Eye Masks(video) on Cadence Online Support. Click the video link now or visit Cadence Online Support and search for the video under Video Library.
Note: If you don’t have a Cadence Online Support account, you can play this video (mp4) natively in Cadence Help when you are using Virtuoso IC6.1.7/ ICADV12.3 (ISR8 or later). In the Cadence Help Virtuoso Documentation Library, look for the video title under Video Demos.
Related Resources
Note: For more information on Cadence products and services, visit www.cadence.com
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Arja Hunkin