Quartus release

what version have you used,

and what version are you now using ?

what messages do you get when you try to open your existing projects ?

could you please provide more informations.

Thanks Mr Schmitt ,

Previous version was 9.0 and now it's 9.1

when I try to open the existing (9.0) project the Quartus message is:

".... The database format is incompatible with the current version of QuartusII software. Overwriting the database does not afect the design files or other source files, but removes all database files for the revision included in the project.... "

Then , if I click "Yes", the database of the previous compilation is cleared !

and I have to recompile all the design with a different result !

yes, the message is correct and normal.

you have upgraded to 9.1SP2 ?

yes, you must recompile as you use a different version of quartus if you want to use the new features or enhancement of the new version or servicepack

could you explain what you mean with different result ?

even a recompile with the same version could lead into a different image, but the behavioral should be the same.

No, I didn't upgrade to Service Pack 2, but is it a problem ?

For different result, I mean a different place and route with a slightly diff timing !

it shouldn't be a problem, but you could have a look at the errata explaining the differences

you could also get slightly different results when you compile a project and recompile it again even with no changes.

if you don't change any settings or RTL, you should get the same fit results on consecutive compiles on the same version of software.

you might try exporting a post-fit QXP from the previous version and import it into the new version.