IOSTANDARD user constrain

Two things to try (there may be warnings or errors for either or both):

INST * IOSTANDARD LVTTL; INST PADS(*) IOSTANDARD LVTTL;

The synthesizers will sometimes allow a global IOSTANDARD default such as the syn_pad_type attribute in SynplifyPro.

Oh yes, it rings the bell by using wild card *, but I will use it with some prefixs

NET XYZ* IOSTANDARD = LVTTL;

The 100% wild card " INST * " generate tons of warnings, it takes almost forever :)

Thanks,

If you don't plan to change your I/O names too often, setting hundreds of pins to the same IOSTANDARD shouldn't be too much of work (may be just a matter of global replacement of an expression). Or you may find ADEPT tool

very useful, which allows you to set IOSTANDARD for multiple pins at once.

Cheers, Jim

Hi All,

PlanAhead 9.1 has been enhanced to have a Pin Planning environment. You can download this tool at

A flexlm based license is required to use PlanAhead, but you can get this for free for a month using the "eval" button on the page.

For the specific functionality you are looking for:

1. Create a PlanAhead project
2. Tools->Open PinAhead...
3. Flatten the table in I/O ports table (toggle the group by interfaces/busses button on the side of this table)
4. Select all I/O ports in the I/O ports and right mouse button to "Configure Ports..."
5. Change the I/O standard to LVTTL
6. File->Export Floorplan to get the UCF out.

Regards, Salil