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Design Languages >> Verilog-AMS >> fork join block
https://designers-guide.org/forum/YaBB.pl?num=1295879383

Message started by Deb on Jan 24^th, 2011, 6:29am

Title: fork join block
Post by Deb on Jan 24^th, 2011, 6:29am

Dear All,

Please help me in the following issue.

I am giving here a code snippet. Please look into this.

///////////////////////////////////////////////////////////////////////////////

fork : globalOperator

real timeOfStart;
integer setMatchHigh;
real timeOfMatch;

timeOfStart = $abstime;
$display("Fork Entered for %d time and timeOfStart for this fork is %f: \n", countStart, timeOfStart);

/* forever begin
while (($abstime - timeOfStart) < delay)
begin
if(!setExpr)
begin
$display("Expr became low before delay time exceeded and hence Thread disabled. \n");
disable globalOperator;
end
else
begin
match = 1'b0;
end
end
end

forever begin
@(cross(($abstime - (timeOfStart + delay)), +1, TimeTolerance))
begin
setMatchHigh = 1;
$display("setMatchHigh is made high. \n");
timeOfMatch = $abstime;
end
end

if(setExpr && setMatchHigh)
begin
match = 1'b1;
countMatch = countMatch + 1;
end

@(cross(($abstime - (timeOfMatch + KeepMatchHighTime)), +1, TimeTolerance))
begin
if(match)
begin
match = 1'b0;
$display("%d Match was detected and match signal is made low: \n", countMatch);
disable globalOperator;
end
end
join

end

//////////////////////////////////////////////////////////////////////////

Within the fork block, after each thread is created, I want to check setExpr for delay value after timeOfStart. For that I have used the while loop but its basically stalling the simulation. How can I do that within the fork block? Please suggest. Also please suggest how can I use a cross statement within the fork block.

Thanks in advance for your kind support.

------------------------------
Thanking you,

Yours sincerely,
Debjit
======================
Debjit Pal

Title: Re: fork join block
Post by Marq Kole on Feb 2^nd, 2011, 6:17am

There is no delay in your while loop, so it will continue to evaluate the code, never progressing through time. If you add a delay anywhere in the loop the while loop will probably work. However, this is a kind of "polling"technique which is quite costly in terms of performance and only as accurate as the delay value you specify. You might want to rework this into an event-driven test case, for instance an event that triggers on any change in setExpr.

Cheers,
Marq

Title: Re: fork join block
Post by Deb on Feb 2^nd, 2011, 7:42am

Hi Marq,

Yep !! You are very correct.. I am implemented it already in other fashion with a concept of loop unrolling.. But anyways.. Thanks for your kind support...

Yours sincerely,

Debjit .

Debjit Pal.