FW: [sv-ec] sum of randcase weights and $urandom_range

-----Original Message-----
From: Yum, Sunny
Sent: Friday, April 09, 2004 3:08 PM
To: Ryan, Ray
Subject: FW: [sv-ec] sum of randcase weights and $urandom_range

Ray,

Can you forward this message to the sv-ec list? I thought I sent it out,
but it never got reflected for some reason. Am I sending the message to the
correct email address?

-Sunny

-----Original Message-----
From: Yum, Sunny
Sent: Wednesday, March 31, 2004 12:52 PM
To: sv-ec@server.eda.org
Subject: [sv-ec] sum of randcase weights and $urandom_range

According to section 12.15 of the LRM:

"Randcase statements exhibit thread stability. The random numbers are
obtained from $urandom_range, thus, random values drawn are independent of
thread execution order."

If the random number used to select a specific item from a randcase
construct is obtained from $urandom_range, does this mean that the sum of
the weights specified by the randcase items must evaluate to an "int
unsigned" type? Note that $urandom_range returns an "int unsigned" result.
This would imply that the compiler/simulator would have to issue an error if
the sum of weights evaluates to a value greater than (2^32)-1.

Or, is the sum of randcase weights unbounded? This would imply that the
random number used to select an item from a randcase construct is coming
from a function similar to $urandom_range, but not $urandom_range (i.e. a
function that exhibits thread stability and returns a random number within a
specified range, but not having fixed precision).

Regards,
Sunny
Received on Fri Apr 9 15:11:40 2004