RE: [sv-bc] Are modport port directions enforced?

20.4 says,

"The keyword modport indicates that the directions are declared as if
inside the module."

 

So it is like declaring d as an input within the module.

 

Shalom

 

 

________________________________

From: owner-sv-bc@server.eda.org [mailto:owner-sv-bc@server.eda.org] On
Behalf Of Francoise Martinolle
Sent: Monday, February 26, 2007 11:48 PM
To: Mark Hartoog; sv-bc@server.eda-stds.org
Subject: RE: [sv-bc] Are modport port directions enforced?

 

There is nothing in the modport description which supports what you are
saying and the port connection rules

for interface only state:

 

19.12.3 Port connection rules for interfaces

A port declaration can be a generic interface or named interface type.
An interface port instance must always

be connected to an interface instance or a higher level interface port.
An interface port cannot be left

unconnected.

If a port declaration has a generic interface type, then it can be
connected to an interface instance of any

type. If a port declaration has a named interface type, then it must be
connected to an interface instance of

the identical type.

 

	 

	
________________________________


	From: Mark Hartoog [mailto:Mark.Hartoog@synopsys.com] 
	Sent: Monday, February 26, 2007 4:43 PM
	To: Francoise Martinolle; Mark Hartoog; sv-bc@eda-stds.org
	Subject: RE: [sv-bc] Are modport port directions enforced?

	There is no continuous assignment to the whole interface, but
there is a continuous assignment to the variables/nets that the modport
makes input ports. If you do not have a modport, then the variables
would be ref ports, and there would be no continuous assignment. 

		 

		
________________________________


		From: Francoise Martinolle [mailto:fm@cadence.com] 
		Sent: Monday, February 26, 2007 1:35 PM
		To: Mark Hartoog; sv-bc@eda-stds.org
		Subject: RE: [sv-bc] Are modport port directions
enforced?

		Mark,

		 

		The modport port is what is connected to the port named
"i" of the module duv. The port named "i"

		has no explicit direction. Furthermore a modport can be
a collection of ports, one may be input, the other output, another
inout.

		I do not see how you can apply the rule of a single
assignment to a variable in my example.

		There is no continuous assignment to the modport "in" of
the module duv.

		 

		Francoise

		       '

			 

			
________________________________


			From: Mark Hartoog
[mailto:Mark.Hartoog@synopsys.com] 
			Sent: Monday, February 26, 2007 4:30 PM
			To: Francoise Martinolle; Mark Hartoog;
sv-bc@eda-stds.org
			Subject: RE: [sv-bc] Are modport port directions
enforced?

			When you instantiate the module, there is an
implicit continuous assignment to the input port. If there is another
continuous or procedural assignment inside the module to the port, then
that violates the one continuous assignment or one or more procedural
assignment rules for variables. This is covered in section 6.7 and 11.5.

				 

				
________________________________


				From: Francoise Martinolle
[mailto:fm@cadence.com] 
				Sent: Monday, February 26, 2007 1:19 PM
				To: Mark Hartoog; sv-bc@eda-stds.org
				Subject: RE: [sv-bc] Are modport port
directions enforced?

				Where is the LRM text supporting your
answer?

				 

				
________________________________


				From: Mark Hartoog
[mailto:Mark.Hartoog@synopsys.com] 
				Sent: Monday, February 26, 2007 4:17 PM
				To: Francoise Martinolle;
sv-bc@eda-stds.org
				Subject: RE: [sv-bc] Are modport port
directions enforced?

				If it is a variable, as in your example,
it should be an error. If it is a net, then you might argue it should be
allowed.

				 

				
________________________________


				From: owner-sv-bc@eda.org
[mailto:owner-sv-bc@eda.org] On Behalf Of Francoise Martinolle
				Sent: Monday, February 26, 2007 1:08 PM
				To: sv-bc@eda-stds.org
				Subject: [sv-bc] Are modport port
directions enforced?

				I have a question regarding the modport
port directions.

				If I declare a modport port in an
interface with direction input, should it be an error

				if the module which uses this modport
tries to assign to the modport port of direction input?

				 

				I cannot find anything in the LRM which
talks about modport port direction enforcements.

				interface data_if ();

				 

				logic [31:0] d;

				 

				modport in  (input d);

				modport out (output d);

				 

				endinterface: data_if

				 

				module duv (data_if.in i, data_if.out
o);

				 

				assign i.d = o.d;     ====> is this
allowed?

				 

				endmodule: duv

				 

				endinterface: data_if

				
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