Encore SIM EDITOR SOFTWARE Podręcznik Użytkownika Pobierz pdf (Strona 122)

3-14

Compiling and Elaborating Your Design

Note:

The -parameters and -pvalue options do not work with a

localparam or a specparam.

Checking for X and Z Values in Conditional Expressions

The -xzcheck compile-time option tells VCS to display a warning

message when it evaluates a conditional expression and finds it to

have an X or Z value.

A conditional expression is of the following types or statements:

• A conditional or if statement:

if(conditional_exp)

$display("conditional_exp is true");

•A case statement:

case(conditional_exp)

1’b1: sig2=1;

1’b0: sig3=1;

1’bx: sig4=1;

1’bz: sig5=1;

endcase

• A statement using the conditional operator:

reg1 = conditional_exp ? 1’b1 : 1’b0;

The following is an example of the warning message that VCS

displays when it evaluates the conditional expression and finds it to

have an X or Z value:

warning ’signal_name’ within scope hier_name in file_name.v:

line_number to x/z at time simulation_time

1 2 ... 117 118 119 120 121 122 123 124 125 126 127 ... 148 149

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Encore SIM EDITOR SOFTWARE Podręcznik Użytkownika Strona 122