RE: [sv-ac] comments on mantis 1550 proposal

John, please see below.
ed 

> -----Original Message-----
> From: owner-sv-ac@eda.org [mailto:owner-sv-ac@eda.org] On 
> Behalf Of John Havlicek
> Sent: Tuesday, February 06, 2007 9:40 AM
> To: sv-ac@eda-stds.org
> Subject: [sv-ac] comments on mantis 1550 proposal
> 
> Ed:
> 
> Below are my comments.
> 
> J.H.
> 
> Comments on Sampled1550.070202.htm
> ----------------------------------
> 
> - "The value of $sampled is updated in the preponed 
> scheduling region."  This is 
>   consistent with "The value is stable throughout the 
> timestep."  Note, however,
>   that in the document that Cliff sent out it says that 
> 
>      Sampling in the Preponed region is equivalent to sampling in the
>      previous Postponed region.
> 
>   Do you know if it is possible for PLI calls in the Postponed and
>   Preponed regions to see a difference between updating $sampled in
>   the Preponed rather than the previuos Postponed region?

I do not believe so because you cannot schedule events into te postponed
region.

> 
> - In the following
> 
>     For example, if $sampled(y) is called at time 0, and y is of type
>     logic, the value returned is X.
> 
>   I'm not sure "y" has been specified enough -- shouldn't we say that 
>   y is not a static variable with declaration assignment?

Either that or give the declaration as 
logic y;
as an example.


> 
> - There seems to be a divergence between $past and $rose, 
> etc. when the
>   clock tick is before the start of simulation.  For $past, 
> shouldn't we 
>   change
> 
>     If the specified clock tick in the past is before the start of
>     simulation, the returned value from the $past function is the
>     value assigned in the declaration of the variable if the argument
>     is a static variable, or in the absence of such an assignment or
>     if the argument is an expression then it is the default value of
>     the type of the argument.
> 
>   to
> 
>     If the specified clock tick in the past is before the start of
>     simulation, the returned value from the $past function is the
>     result of evaluating the expression using the initial values of
>     the variables comprising the expression. The initial value of a
>     static variable is the value assigned in its declaration, or in
>     the absence of such an assignment it is the default (or
>     uninitialized) value of the corresponding type. The initial value
>     of any other variable or signal is the default value of the
>     corresponding type.

The current text on Mantis is:

When these functions are called at or before the first clock tick of the
clocking event, the results are computed by comparing the current
sampled value of the expression to the result of the expression
evaluated using the initial values of the variables comprising the
expression. The initial value of a static variable is the value assigned
in its declaration, or in the absence of such an assignment it is the
default (or uninitialized) value of the corresponding type. The initial
value of any other variable or signal is the default value of the
corresponding type.

?

> 
>   ?
> 
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