FPGA Central

Some of the xilinx fpga pins are wired to leds. P39 for instance is
wired in such a way. In my design I have a vhdl counter and want to
direct ISE (v.6.3i) to tie the output of the counter to P39. What is
the way to do this?

It seems that PACE does this, but then Floorplanner and FPGA Editor
seem to do something similar to this as well. When I tried to use PACE,
I saw I could specify the Loc as "BANK6", but could not figure out how
to directly assign to the pin #. In Floorplanner I could select
File->Read Constraints..., but wasn't sure this would do what I wanted
either.

In Xilinx ECS I could create a schematic that wires together the vhdl
counter. It occurs to me that this is also a possible place to assign
the output to P39. Is that true?

Thanks,
-beagle

IMO, the easiest to do this is in a UCF file.
If you like PACE, it will create one for you.
Otherwise, take an existing (non trivial) ucf, and modify it.
Beware of busses notation, between <>, (), and [] !
Make sure your ucf text file is in your projnav, attached to your
top level entity. And make sure you dont ask for the option to "ignore" it !!!

Bert

[email protected] wrote:

> Some of the xilinx fpga pins are wired to leds. P39 for instance is
> wired in such a way. In my design I have a vhdl counter and want to
> direct ISE (v.6.3i) to tie the output of the counter to P39. What is
> the way to do this?
>
> It seems that PACE does this, but then Floorplanner and FPGA Editor
> seem to do something similar to this as well. When I tried to use PACE,
> I saw I could specify the Loc as "BANK6", but could not figure out how
> to directly assign to the pin #. In Floorplanner I could select
> File->Read Constraints..., but wasn't sure this would do what I wanted
> either.
>
> In Xilinx ECS I could create a schematic that wires together the vhdl
> counter. It occurs to me that this is also a possible place to assign
> the output to P39. Is that true?
>
> Thanks,
> -beagle
>

Hi,
I had the same problem too.
PACE:
Click on the package view tab at the bottom of the screen. This will
show you all the BGA package pins and their functions ( I/O, clock, Gnd
etc) on a nice graphic. Next drag the module port name from the left of
the screen to an appropriate pin on the package pin diagram and drop
it.

Then just save and exit. The UCF file will show up on your projNav.

Kunal