Trying to access internal design signal by using an abstract interface

In reply to dave_59:

Hi,

I am not getting X’s on input ports but it’s not driven by WData.(I/P port always remain with the previous value)

If I define the interface probe_itf #(int WIDTH) (inout wire [WIDTH-1:0] WData);
I am getting following error
“Expression connected to an ‘inout’ port must be collapsible”

Thanks.
Karan