cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Highlighted
Contributor
Contributor
9,334 Views
Registered: ‎01-02-2015

Net connections for unused GTX transceivers.

Jump to solution

I am designing a carrier card for the PicoZed 7030. The design will not make use of the GTX transceivers at all. From table 5-6 of UG476, I understand that the following connections should be made for the unused transceivers:

MGTAVCC -> GND
MGTAVTT -> GND

MGTVCCAUX -> GND

MGTREFCLKP/MGTREFCLKN -> Open

MGTRXP/MGTRXN -> GND

MGTTXP/MGTTXN -> Open

MGTRREF -> GND

 

Three questions:

Can anyone verify that this is correct?

 

MGTVCCAUX is already connected to 1.8V on the PicoZed. Is there any reason to not leave this connected as is?

 

Is there anything on the PicoZed other than the transceivers that use MGTREFCLKP/N, MGTAVCC, and MGTAVTT? It would be a shame to make these boards and find out that the ethernet controller doesn't work.

 

 

 

 

0 Kudos
Reply
1 Solution

Accepted Solutions
Highlighted
Professor
Professor
17,600 Views
Registered: ‎08-14-2007

If your board already has power to the MGT, then it's best to leave it.  Unused MGTs won't use much power.  The best recommendation is to treat this as a partially unused GTX quad, so just ground the unused MGTRXP/MGTRXN inputs.

-- Gabor

View solution in original post

3 Replies
Highlighted
Professor
Professor
17,601 Views
Registered: ‎08-14-2007

If your board already has power to the MGT, then it's best to leave it.  Unused MGTs won't use much power.  The best recommendation is to treat this as a partially unused GTX quad, so just ground the unused MGTRXP/MGTRXN inputs.

-- Gabor

View solution in original post

Highlighted
Moderator
Moderator
9,298 Views
Registered: ‎02-16-2010
The guidance mentioned in ug476 is correct

The clock on MGTREFCLKP/N ports can be used for fabric logic by forwarding it using a BUFG. This will be useful even when MGTs are not used in the design.

MGTAVCC, MGTAVTT are only used for transceivers.
------------------------------------------------------------------------------
Don't forget to reply, give kudo and accept as solution
------------------------------------------------------------------------------
Highlighted
Xilinx Employee
Xilinx Employee
9,294 Views
Registered: ‎08-01-2012

Also refer http://www.xilinx.com/support/answers/41451.html

________________________________________________

Please mark this post as an "Accept as solution" in case if it helped to resolve your query. So that it will help to other forum users to directly refer to the answer.

Give kudos to this post in case if you think the information is useful and reply oriented.