FW: Some merged_datatype.pdf feedback.

Resend for Ken Kundert.

Shalom

-----Original Message-----
From: owner-verilog-ams@server.verilog.org On Behalf Of Ken Kundert
Sent: Monday, June 05, 2006 10:13 PM
To: Graham Helwig
Cc: VerilogAMS Reflector
Subject: Re: Some merged_datatype.pdf feedback.

Graham,
    Thanks for your response. I took a look at your syntax and here is
what I found.

It still appears that an event trigger (->) is not allowed in an analog
block.

I noticed that when declaring named events that they can be declared
with dimensions, but that the syntax for the event control statements do
not support specifying the dimension.

Finally, I noticed that @* and @(*) are valid event control statements
in the digital context but not in the analog. I have no idea what they
mean, but I thought I would point out the inconsistency.

-Ken

Graham Helwig wrote:
> Hello Ken,
> 
> Please see my comments below:
> 
>> 1. In the 2.2 LRM the event_control syntax definition seems
ambiguous.
>>    The event_control statement is defined in terms of an
>>    event_expression, but an event_expression is never defined. Rather
>>    analog_event_expression and digital_event_expressions are defined,
>>    but it is never made clear how they relate to an event_expression.
>>   2. It does not appear as if one can trigger a named event within an
>>    analog block (the -> operator is not mentioned in the 2.2 LRM from
>>    what I can tell).
>>   
> 
> I'm aware of a number of these event expression related problems in
LRM
> 2.2. Have a look at the event expression syntax of
>
http://www.verilog.org/verilog-ams/htmlpages/public-docs/merged_syntax.p
df.
> Does this address your needs?
> 
>> 3. A change in an analog discrete variable (an integer) cannot
trigger
>>    a change in a continuous assignment nor in an event expression.
>>    (This is ambiguous in the LRM and not allowed in the Cadence
>>    implementation.)
>>   
> 
> Agreed, it would be help for continuous assignment statements to be
> sensitive to discrete integer variables. IF this is to be allowed then
> it should be document in section 6.
> 
>> Note, between restrictions 2 & 3, it is not possible to have analog
>> behavior trigger changes in digital signals without there being a
cross
>> function involved, and and one cannot use cross functions on
integers.