FMC Carrier Breakout Cards

Question

Has anyone had any luck using a "breakout" FMC carrier card with the Picozed? I've found a few that I'd like to try out, but would like to see if the community has used any with success:

1) From Xilinx (this one seems promising?): http://www.xilinx.com/products/boards-and-kits/hw-fmc-xm105-g.html#overview

2)From Kaya Instruments: http://www.kayainstruments.com/fmc-prototype-board/

3) From Altauri (breadboards are notoriously terrible for high-speed applications, but worth a shot): http://altauri.com/product/fmc-development-board/

We need "REAL" differential signaling; according to the latest errata for the Picozed FMC Carrier Card, the PL PMOD connectors are inherently broken and don't work with differential signaling, due to level translators.

Any thoughts or comments?

-Ron

bhfletcher · Accepted Answer

Ron,

We have had a couple people attempt to port the designs for their high-speed, off-the-shelf FMC Cards without success.

Opsero's http://ethernetfmc.com/
Avnet's http://www.em.avnet.com/en-us/design/drc/Pages/HDMI-Input-Output-FMC-module.aspx)

The reason is due to the pinout chosen on the PicoZed FMC Carrier, which did not aggregate adjacent pairs on banks. For example, if you look at the MicroZed FMC Carrier, it places FMC Pairs 0 to 16 on Bank 34 and Pairs 17 to 33 on Bank 35. For a timing critical design like the ethernet or HDMI modules, they depend on certain I/Os to be on just one bank. On the PicoZed FMC Carrier, they are not, which causes timing errors when built to that pinout. This is documented in Section 4.7 of the PicoZed FMC Carrier Errata.

That said, there are no electrical problems of which we are aware. If you are looking to use a prototype board to gain access to the pairs, I see no problem with this as you will control which pairs you are using. We have used the XM105 successfully in the past.

For those that need high-speed, off-the-shelf FMC cards to work with PicoZed, we are working on a redesign of the carrier that corrects the FMC pinout. We expect this to be available in Q1. In the meantime, the alternatives include the MicroZed FMC Carrier, Zynq MMP, Zynq Mini-ITX, or ZC702.

The statement regarding differential signaling over the PicoZed FMC Carrier Pmods is correct -- it won't work. We are also looking to correc this in the redesign. The MicroZed FMC Carrier does this correctly, and we have tested TMDS33 successfully with the Avnet Touch Display on that board.

Bryan