How to write top module

I have a design , one testbench for the design
but 3 inputs of design is generating from external module..
And the rest of all inputs i'm giving from testbench ( those 3 inputs
i can't provide from testbench)
so how i can write a top module for these three modules ...
can any one tell me how these 3 inputs i can pass to design..

 

[mjl296@hotmail.com]

On 16 Sep, 13:23, pradeeps...@gmail.com wrote:

I have a design , one testbench for the design
but 3 inputs of design is generating from external module..
And the rest of all inputs i'm giving from testbench ( those 3 inputs
i can't provide from testbench)
so how i can write a top module for these three modules ...
can any one tell me how these 3 inputs i can pass to design..

The top module of the testbench shouldn't have any inputs because the
simulator will have no way of knowing what to do with them. If these
inputs will be driven from an external module in hardware, then you
must provide a model of this external module in the testbench. How you
write such a model will depend on the nature of the external module.