I designed a pulse oximeter circuit for FPGA with kicad…Before sending it to manufacturer i want to check/test/verify different signals like Input output for few buffers, chip select for different ICs,voltage levels etc. I dont have any prior experience with PCB design so can you guide me how to do this.
To me, it sounds like you are asking about circuit simulation rather than PCB design - and your description is rather general.
Oops . . . . I see you have already posted in the “Simulation (NGSpice)” category. Can you be a little more specific about what you are trying to verify? Do you have valid SPICE models for the components in your design? KiCAD’s interface to NGSpice is not my area of expertise, so we need a Forum member with that knowledge to help you out.
NGspice is the simulator that is suported by kicad. If you want to use a different one then you will need to use the schematic tool of that simulator to use it. (Or you find a netlist generator for your simulator of choice that can use kicad data as its input.)