regarding config pins voltage levels

[kd9]

will we connect nstatus, nconfig, and config_done to 2.5V in cyclone 10LP in PS mode? These signals are going to processor/DSP(ADSP-BF534BBC-4A) that's working on 3.3v logic(attached the acceptance logic voltages for DSP). Can you please guide us on do we need to connect these pin to 2.5v only or it is working fine on 3.3v in CYCLONE 10 LP.

Do we need to connect unused CLK to GND. is it recommended or it should be grounded ? 

[FvM · Accepted solution]

Hello,

in case of doubt follow the Cyclone 10 LP Device Family Pin Connection Guidelines strictly.

If using a 3.3V PS configuration host, I would prefer to power the respective VCCIO with 3.3V, but 2.5V should work as well. In any case, the warnings about maximal FPGA input voltage should be observed and measures against possible overshoot of externally driven signals taken, e.g. source series termination. 

There faults in your schematic snippet like 10k terminated MSEL2 pin.

Unused CLK inputs are flagged as GND+ in the pin list, means, they should be connected to ground or another signal. See also pib connection guidelines.

Frank