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["Timothy Fanelli" <tfanelli@xxxxxxxxxxxx>]

** Sorry if many of you got this twice, I replied to the wrong forum originally 
(help forum) - wanted to make sure it got back to the right place **
 
Dhekra,

I assume here that Q2, Q1 and U2 are ports in a module? What you are seeing is 
the effects of a "delayed update" - even though you appear to have written a 
new value to Q2, it will retain its new value until the next delta cycle (in 
other words, new values are assigned during the update cycle at the end of each 
processing cycle).

There are two ways I see to work around this in your problem:

1) Assign (Q2.read() + Q1.read()) to some local variable in your method, then 
write that variable to Q2 and use it in the calculation of the value written to 
U2 as well. For example:

int temp = Q2.read() + Q1.read();
Q2.write( temp ) ;
U2.write(C2.read()*temp);

2) (IF you're implementing an SC_THREAD or SC_CTHREAD, this /should/ work, but 
not recommended other than to learn about the delta-cycles and how they work): 
Force an update-cycle delay by inserting a wait(SC_ZERO_TIME) statement in 
between the two write statements. This will not advance simulation time, but 
rather will cause the current thread to block and wait until an update-cycle 
occurs, then pick up and execute again. There may be other unintended 
consequences later depending on the complexity of your model. It is also not a 
realistic thing to do if you are doing hardware design. But, for educational 
purposes when I first started learning SystemC, it was interesting to play with 
to get a hang for the update-cycle delays.


Thanks,

Timothy C. Fanelli

Instructor, PhD Student
Software Engineering
Department of Electrical and Computer Engineering
Clarkson University, Potsdam, NY 13699



On Dec 1, 2009, at 8:53 AM, KEDIDI DHEKRA wrote:

Hi again!
I have another problem when simulation:
When I put in my code:
Q2.write( Q2.read()+ Q1.read() ) ;

U2.write(C2.read()*Q2.read());}

in simulation the value of U2 is calculated with the previous value of Q2 not 
the new value calculated in the equation:Q2.write( Q2.read()+ Q1.read() ) ;

how to solve this porblem??

thanks a lot...

best regards

Dhekra