Forum Discussion
FvM
Super Contributor
2 months agoHi,
the missing link between above quoted datasheet table 8 (recommended Vi = -0.5 .. 3.6 V) and table 20 (Vih,max = Vccio + 0.3V) is the fact, that PCI clamp diodes are enabled in Quartus software for most IO standards by default.
You have to decide if your circuit involves possible input overshoot so that PCI clamp diodes must stay enabled to protect the FPGA or if they can be explicitely disabled.