I need some help selecting the optimum voltage for VIO1. In particular, I am interested in anyone's real-life experience of using different voltages (1.8, 2.5, and 3.3 volts) at different frequencies. For example, if the FX3 is operated at 100 MHz, can the I/Os be truly driven at 3.3 volts?, Or do I need to go for 1.8 volts to minimize noise?
What would be (really) nice to have is a table that shows the maximum frequency that can be reliably achieved at each voltage.
You can use any one of the voltage domains (1.8 V, 2.5 V or 3.3 V) to make the GPIF-II interface work reliably at 100 MHz.