Encore SIM EDITOR SOFTWARE Guida Utente Scaricare il pdf (Pagina 79)

2-11

Modeling Your Design

An example of the $test$plusargs system function is as follows:

initial

if ($test$plusargs("postprocess"))

begin

$vcdpluson(0,design_1);

$vcdplustraceon(design_1);

$vcsplusdeltacycleon;

$vcdplusglitchon;

end

In this technique you do not include the +define compile-time

argument on the vcs command line. Instead you compile the system

tasks into the testbench and then enable the execution of the system

tasks with the runtime argument to the $test$plusargs system

function. So for this example the simv command line is as follows:

% simv +postprocess

During simulation VCS writes the VPD file with all the information

specified by these system tasks. Later you can execute another simv

command line, without the +postprocess runtime option. As a

result, VCS does not write the VPD file, and therefore runs faster.

There is a pitfall to this technique. This system function will match

any plusarg that has the function’s argument as a prefix. For example:

module top;

initial

begin

if ( $test$plusargs("a") )

$display("\n<<< Now a >>>\n");

else if ( $test$plusargs("ab") )

$display("\n<<< Now ab >>>\n");

else if ( $test$plusargs("abc") )

$display("\n<<< Now abc >>>\n");

end

endmodule

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Encore SIM EDITOR SOFTWARE Guida Utente Pagina 79