Virtex 2 Pro IO Banks Vcco

Hi all,
I'm having the following problem: I'm trying to interface a XUP Virtex-II
Pro Development System with a CMOS camera, and the output voltage on the
board's expansion connectors is 2.5V for logic '1', no matter what
IOSTANDARD is specified in the ucf file. I understand this is because the
Vcco for the io bank is 2.5V. (However, in the schematic it shows that for
the IO Banks that relate to the expansion connectors, Vcco=3.3V.)
My question is if it possible to change the Vcco supply voltage by any
sw/hw means.
Thank you in advance.

On Jun 10, 7:28=A0pm, "Manfred" <octavian_machi...@yahoo.com> wrote:
> Hi all,
> I'm having the following problem: I'm trying to interface a XUP Virtex-II
> Pro Development System with a CMOS camera, and the output voltage on the
> board's expansion connectors is 2.5V for logic '1', no matter what
> IOSTANDARD is specified in the ucf file. I understand this is because the
> Vcco for the io bank is 2.5V. (However, in the schematic it shows that fo=
r
> the IO Banks that relate to the expansion connectors, Vcco=3D3.3V.)
> My question is if it possible to change the Vcco supply voltage by any
> sw/hw means.
> Thank you in advance.

I am having the same issue, but for a different application. I need
3.3V LVTTL outputs, which the expansion points are supposed to be
according to the documentation, but when I measure the outputs against
a 3.3V device, they are too low and resemble 2.5V LVCMOS.

Have you looked at:

http://www.digilentinc.com/Data/Products/XUPV2P/xupv2p-sch.pdf

???

Austin

On Jun 19, 8:41=A0am, austin <aus...@xilinx.com> wrote:
> Have you looked at:
>
> http://www.digilentinc.com/Data/Products/XUPV2P/xupv2p-sch.pdf
>
> ???
>
> Austin

Looks like perhaps the schematic is incorrect if you see 2.5v on a pin
in a bank whose Vcco is 3.3v!

Should email Digilent...

Austin

Manfred wrote:
> Hi all,
> I'm having the following problem: I'm trying to interface a XUP Virtex-II
> Pro Development System with a CMOS camera, and the output voltage on the
> board's expansion connectors is 2.5V for logic '1', no matter what
> IOSTANDARD is specified in the ucf file. I understand this is because the
> Vcco for the io bank is 2.5V. (However, in the schematic it shows that for
> the IO Banks that relate to the expansion connectors, Vcco=3.3V.)
> My question is if it possible to change the Vcco supply voltage by any
> sw/hw means.
> Thank you in advance.
> 

If you are using the LT_USER_IO, these pins are connected through an IDT 
Quickswitch device to FPGA.  The IDT QuickSwitch will clip the waveform 
at approximately VCC - 1V.  The board that you are using has VCC set to 
3.3V, so the output will be limited to ~2.3V under nominal conditions. 
Changing the VCC of the QuickSwitch can not be easily accomplished.

The HS_USER_IO are connected directly from the FPGA to the connector and 
would get you the 3.3V that you are looking for.

Ed McGettigan
--
Xilinx Inc.