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Observer
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Registered: ‎09-06-2016

Ambiguous device view in Vivado

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I'm doing a design for a custom board.  Vivado gives a device view for the implemented device.  I'm using the 2892 fine pitch bga.

The positions of the QUAD GTY blocks seems mirrored in that display when routed compared to the package documentation in UG575 p168.

The package view suggests pin A1 is upper left in a top view because it looks like the package in UG575. 

So where is pin A1 in the both views, i.e., which corner?  

 

Thanks

 

Package 2892.jpg
Unrouted 2892.jpg
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Observer
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Registered: ‎09-06-2016

I finally figured this out.  In the UG575 document, the block diagram is for some reason mirrored left to right on page 173.  Page 57 calls this a "die view" not indicating it is, I think, a bottom view when mounted on the interposer.  Or else they mount it on the interposer circuits up, and then wire bond to the interposer and route from one side to the other?  But why do that?  Maybe the whole interposer is flipped over after bonding?  Once again Xilinx is messing with my mind.

In Vivado the device view is mirrored left to right to match page 173.  But in UG575, the package pin ID on page 342 is not mirrored according to page 180.  The tiny faded pastel color code at the bottom of that page seems to show quad 234 over by pin A1 if you zoom in.  

I wonder how many document links I would have to click through to find where they actually come out and explain this.  I wonder why they could not just show the assembly instead of saying die view for the block/bank diagram.

 

 

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Chip_Layout_37-47p.jpg
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Xilinx Employee
Xilinx Employee
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Registered: ‎03-30-2016

Hello @srdatucsd 

If you are designing a custom board, you only need to check the package view.
Vivado shows package view on top-view by default, but you can change the setting to bottom-view on your Vivado GUI.
TOP_or_BOTTOW_VIEW.png

"A1" is a package pin-name.
There is no "A1" definition in device view, since this view show the die of your device not pins of your device package.
Some device model will have its die mounted upside down in the package, but board designed does not really care about that.

Regards
Leo

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Observer
Observer
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Registered: ‎09-06-2016

Thanks Leo.  But my confusion remains.  Look at the attached implementation.

This used GT QUAD 234 at X7Y10.  From the UG575 diagram, I would expect that quad to be on the right, the opposite side from A1 as shown in the UG575 top view.

But it is apparently on the left next to A1 on the circuit board I am targeting.  This suggests the device view is mirrored left to right.  ??  How can I tell where the GT's I use really are on the package?

In order to get the quads as near as possible to the applicable connector, I need to know whether the routed device view is mirrored or not with respect to the block diagram and the pin diagram.

If it is not mirrored, then there may be a documentation error on the circuit board I am using.

Thanks

Where is X7Y10.jpg
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Observer
Observer
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Registered: ‎09-06-2016

I finally figured this out.  In the UG575 document, the block diagram is for some reason mirrored left to right on page 173.  Page 57 calls this a "die view" not indicating it is, I think, a bottom view when mounted on the interposer.  Or else they mount it on the interposer circuits up, and then wire bond to the interposer and route from one side to the other?  But why do that?  Maybe the whole interposer is flipped over after bonding?  Once again Xilinx is messing with my mind.

In Vivado the device view is mirrored left to right to match page 173.  But in UG575, the package pin ID on page 342 is not mirrored according to page 180.  The tiny faded pastel color code at the bottom of that page seems to show quad 234 over by pin A1 if you zoom in.  

I wonder how many document links I would have to click through to find where they actually come out and explain this.  I wonder why they could not just show the assembly instead of saying die view for the block/bank diagram.

 

 

View solution in original post

Chip_Layout_37-47p.jpg
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