Should i use wire type under inout port?

[u24c02]

Hi

I trying to connent with instance module in my top module in verilog.
Thier's instance have inout port. Then i use "reg" type connent to that port.
So ncverilog's result is port connections to inout ports must be collapsible, they must be nets.
But i can understand why it's error?

Should i use net type to connect with inout port?

 

[kornukhin]

You can't connect 'reg' with inout port in verilog. This is done because 'reg' can't be driven any way except procedural assignment.

If you really need connect this 'reg' to inout (ex., inout will be always in 'input' mode), you can use something like this:

...
reg in_reg;
wire in_wire;
assign in_wire = in_reg;
...
.inout_port(in_wire),
...

 

[dave_59]

See my article on the differences between wires and reg's for an explanation of why this rule exists.