03-15-2013 08:05 AM
I'm trying to figure out if the upcoming AC701 Artix-7 Evaluation Board will support the use of your FMC-DVI Board.
As far as I can tell, there are two requirements for the FPGA Board:
- High Pin Count FMC Connector, with at least the columns H, G, D and C fully populated
- either 2.5V or 3.3V on the VADJ Pins (H40, G39) of the FMC Connector.
Is that correct?
The user guide for the Artix-7 Board lists a HPC-FMC Connector (J30) with populated columns H, G, D and C.
Unfortunately, the FMC-Pinout Table on page 58 of the Artix-7 User Guide lists pins G39 and H40 as connected to "VCC1V8", which seems to indicate a fixed 1.8V on the VADJ pins.
However, the schematic for the Artix-7 board shows those pins as connected to a "VCCO_VADJ" net (page 25), which is connected to a variable voltage regulator (page 46) that supports both 2.5V and 3.3V.
Which document should I trust? I'm hoping it's simply a mistake in the User Guide?
Can I use the FMC-DVI Board with the AC701 Board?
The documentation for the Artix-7 Board can be found here:
03-18-2013 11:00 AM
The FMC-DVI module requires VADJ of 2.5V or 3.3V.
If you are not using the DisplayPort output, and only using the DVI input and output interfaces,
you only need an LPC (low pin count) FMC connector.
According to the AC701 schematics (PDF), VADJ is programmable . The attached image is an exerpt taken from page 38 of the schematics, and seems to indicate that the default value of VADJ is 2.5V.
It may be a good idea to check with Xilinx to confirm that VADJ = 2.5V is the default configuration.