RE: [sv-bc] always_ff

Shalom,
  In that case, given your original question
 
>>The LRM does not today require always_ff to be followed by a
sensitivity list with edge-sensitive event controls. Is that deliberate?
 
I believe the answer is yes, the LRM is correct with the current
sentence
 "The always_ff procedure imposes the restriction that it contains one
and only one event control and no blocking timing controls."

As shown in my example below, you can have a legal always_ff that is not
followed by an edge sensitive event.
 
~Alex
 
 
________________________________

From: Bresticker, Shalom [mailto:shalom.bresticker@intel.com] 
Sent: Thursday, July 03, 2008 2:37 AM
To: Gran, Alex; sv-bc
Subject: RE: [sv-bc] always_ff


Hi, Alex. 
 
A strict reading of the LRM gives the following:


________________________________

	From: Gran, Alex [mailto:alex_gran@mentor.com] 
	Sent: Wednesday, July 02, 2008 7:16 PM
	To: Bresticker, Shalom; sv-bc
	Subject: RE: [sv-bc] always_ff
	
	
	Shalom,
	     Is this legal?  
	 
	[SB] Yes.
	 
	module test(input my_in, clk, output logic my_out);
	 
	always_ff
	        begin
	                @(posedge clk);
	                        my_out = my_in;
	        end
	endmodule
	
	 
	If so, does always_ff follow the rules from 9.4.2.2 'Implicit
event_expression list' for making its sensitivity list?
	[SB] No. That applies only to @*.
	 
	Specifically
	All net and variable identifiers that appear in the statement
will be automatically added to the event expression

	with these exceptions:

	- Identifiers that only appear in wait or event expressions.

	 
	The text in 9.2.2.4 that describes the always_ff behavior says
	 
	"The always_ff procedure imposes the restriction that it
contains one and only one event control and no
	blocking timing controls."
	 
	So in my example is the "@(posedge clk)" the single event
control, thus following the rules.
	[SB] Strictly speaking, yes. 
	 
	Or is there 1 implicit event control on the always_ff and then
the @(posedge clk) is a 2nd, thus breaking the rules.
	 
	[SB] No, there is no implicit event control.
	 
	Regards,
	Shalom

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