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

Cheers, Jim

Hi All,

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

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