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.SDF file syntax - tie star input to 1 or open?


Do you have some documentation regarding the syntax of .SDF files?

For example, how do we tell the .SDF file to tie an input of a star to logic high (1)?

I see that in the VC707+FMC110 reference design .SDF file there is the syntax, tiedto0.

However, when I tried tiedto1, the output constellation top-level .VHD file shows that input still tied to logic low (0).

How do I have an input tied to logic high (1)?  What about open; i.e., how do I have an input tied to open (left floating)?

More generally, do you have some documentation describing the syntax of .SDF files?

Thank you!

Dear Sir,
The 'tiedto0' keyword is the only keyword actually supported. Its purpose is not to tie to a specific voltage level but more like not having unconnected input in VHDL as this is not allowed by VHDL. We decided to always attach those to 0, we could have decided 1 but it is 0. Outputs can be left unconnected but not the inputs.
We do not have extra documentation for the sdf syntax in more than the few examples found in the getting started guide as we are moving towards a StellarIP only supporting Schematic entry where the SDF is only an intermediate file.
Best Regards,
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