Honored Contributor
Honored ContributorIt doesn't sound like you have a problem - unless you are referring to a product that is already shipping... see below.
Make sure your Quartus project pin assignments match your hardware. In the 'Pin Planner' specify the operating voltage for each pin individually. Pins in banks 3 & 4 must be specified as "1.8 V", or another 1.8V compliant standard. Any signal connected to a pin in a 3.3V powered bank, specify accordingly. Do this regardless of any default setting. Alternatively, if you wish to change the default I/O standard for the project, you can. Change it under 'Assignments' -> 'Device...'. Click on the 'Device and Pin Options...' and select the 'Voltage' option on the left. You can then change the default I/O standard to what you want - in your case 3.3V LVTTL or 3.3V LVCMOS. If you're already shipping this design, having compiled it with the incorrect settings, then the only issue you have is that you've not specified your design correctly when you compiled it. This will not damage the device. It may mean the static timing analysis Quartus performed may not be representative of your design. However, you're operating the I/O at a higher voltage than specified. You're only likely to see better than predicted performance as a result. Regards, Alex
