repeat and forever loop
Table of Contents
repeat loop
repeat will execute the statements within the loop for a loop variable number of times.
if the loop variable is N, then the statements within the repeat block will be executed N number of times.
repeat loop syntax
repeat(<variable>) begin //statement - 1 ... //statement - n end
statements 1-n will be executed for a variable value number of times.
repeat loop example
In the below example,
repeat loop value is 4, so the statements within the repeat loop will be executed for 4 times.
module repeat_loop;
int a;
initial begin
$display("-----------------------------------------------------------------");
repeat(4) begin
$display("\tValue of a=%0d",a);
a++;
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of a=0 Value of a=1 Value of a=2 Value of a=3 -----------------------------------------------------------------
forever loop
As the name says forever loop will execute the statements inside the loop forever.
It can be said as indefinite iteration.
forever loop syntax
forever begin //statement - 1 ... //statement - n end
forever loop example
module forever_loop;
int a;
initial begin
$display("-----------------------------------------------------------------");
forever begin
$display("\tValue of a=%0d",a);
a++;
#5;
end
$display("-----------------------------------------------------------------");
end
initial begin
#20 $finish;
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of a=0 Value of a=1 Value of a=2 Value of a=3 $finish called from file "testbench.sv", line 27. $finish at simulation time 20