break and continue
Table of Contents
break
The execution of a break statement leads to the end of the loop.
break shall be used in all the loop constructs (while, do-while, foreach, for, repeat and forever).
syntax
break;
break in while loop
module break_in_while_loop;
int i;
initial begin
$display("-----------------------------------------------------------------");
i = 8;
while(i!=0) begin
$display("\tValue of i=%0d",i);
if(i == 4) begin
$display("\tCalling break,");
break;
end
i--;
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of i=8 Value of i=7 Value of i=6 Value of i=5 Value of i=4 Calling break, -----------------------------------------------------------------
break in do while loop
module break_in_do_while_loop;
int i;
initial begin
$display("-----------------------------------------------------------------");
i = 8;
do begin
$display("\tValue of i=%0d",i);
if(i == 4) begin
$display("\tCalling break,");
break;
end
i--;
end
while(i!=0);
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of i=8 Value of i=7 Value of i=6 Value of i=5 Value of i=4 Calling break, -----------------------------------------------------------------
break in a foreach loop
module foreach_loop_break;
int a[4];
initial begin
$display("-----------------------------------------------------------------");
foreach(a[i]) a[i] = i;
foreach(a[i]) begin
$display("\tValue of a[%0d]=%0d",i,a[i]);
if(i == 2) begin
$display("\tCalling break,");
break;
end
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of a[0]=0 Value of a[1]=1 Value of a[2]=2 Calling break, -----------------------------------------------------------------
break in for loop
In below example,
when the loop value equals 4, the break is called this leads to the end of the loop.
module break_in_loop;
initial begin
$display("-----------------------------------------------------------------");
for(int i=0;i<8;i++) begin
$display("\tValue of i=%0d",i);
if(i == 4) begin
$display("\tCalling break,");
break;
end
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of i=0 Value of i=1 Value of i=2 Value of i=3 Value of i=4 Calling break, -----------------------------------------------------------------
break in repeat loop
module repeat_loop_break;
int i;
initial begin
$display("-----------------------------------------------------------------");
repeat(5) begin
$display("\tValue of i=%0d",i);
if(i == 2) begin
$display("\tCalling break,");
break;
end
i++;
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of i=0 Value of i=1 Value of i=2 Calling break, -----------------------------------------------------------------
break in forever loop
module forever_loop_break;
int i;
initial begin
$display("-----------------------------------------------------------------");
i = 5;
forever begin
$display("\tValue of i=%0d",i);
if(i == 2) begin
$display("\tCalling break,");
break;
end
i++;
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- Value of i=0 Value of i=1 Value of i=2 Calling break, -----------------------------------------------------------------
Continue in SystemVerilog
Execution of continue statement leads to skip the execution of statements followed by continue and jump to next loop or iteration value.
syntax
continue;
Continue example
In below example,
when ever the loop value is with in 3 to 6, continue statement will be executed, this leads to skip the execution of display statement after the continue.
module continue_in_loop;
initial begin
$display("-----------------------------------------------------------------");
for(int i=0;i<8;i++) begin
if((i > 2) && (i < 7))begin
$display("\t\tCalling continue,");
continue;
end
$display("\t\tAfter Continue\t:: Value of i=%0d",i);
end
$display("-----------------------------------------------------------------");
end
endmodule
Simulator Output
----------------------------------------------------------------- After Continue :: Value of i=0 After Continue :: Value of i=1 After Continue :: Value of i=2 Calling continue, Calling continue, Calling continue, Calling continue, After Continue :: Value of i=7 -----------------------------------------------------------------