User guide

18-1

DirectC Interface

DirectC Interface 3

DirectC is an extended interface between Verilog and C/C++. It is an

alternative to the PLI that, unlike the PLI, enables you to do the

following:

• More efficiently pass values between Verilog module instances

and C/C++ functions by calling the functions directly, along with

actual parameters, in your Verilog code.

• Pass more kinds of data between Verilog and C/C++. With the

PLI you can only pass Verilog information to and from a C/C++

application. With DirectC you do not have this limitation.

With DirectC, for example, you can model a simulation environment

for your design in C/C++ in which you can pass pointers from the

environment to your design and store them in Verilog signals, then

at a later simulation time pass these pointers to the simulation

environment.