Cocotb VHDL required for FLI

Question

I am currently setting up a Cocotb-based validation environment.

I just found that the example provided by Cocotb does not work in my case if VHDL is used, because my simulator does not have a FLI interface (foreign language interface). I get the following message:

Error (suppressed): (vsim-FLI-3155) FLI is not included in this version of ModelSim.

(I have a version of Altera Starter ModelSim, and even FLI is not included).

What surprises me is that the example works with Verilog. In my opinion, Verilog does not use FLI, but VPI.

Can someone explain to me a little if the need for FLI is mandatory, and what feature can enable it in Cocotb?

Another question: what if my top is in Verilog, but the rest of my design is in VHDL? Should it work?

Answer 1

Cocotb has an internal abstraction layer (GPI) for FLI , VPI, and VHPI . For instance. if you use Cocotb with GHDL , it uses only VPI. You can try compiling Cocotb against VPI instead of FLI and load the VPI library instead of the FLI library.