need some explanations for "–loop_iteration_limit"

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Matrix_YL

Joined: 19 Aug 2005
Posts: 107
Helped: 2

27 Sep 2005 14:00 loop_iteration_limit

Hi all

I learn XST manual and meet some questions about While LOOPS
I found this in that manual

1.To prevent endless loops, use the "–loop_iteration_limit" switch.
2.While loops can have Disable statements. The Disable statement must be use inside a labeled block, since the syntax is "disable<blockname>."

who can give me some example for 2 and told how to set the "–loop_iteration_limit" switch:|

thank you very much !

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nand_gates

Joined: 19 Jul 2004
Posts: 907
Helped: 120

28 Sep 2005 5:48 set loop iteration limit

http://www.lavalogic.com/xlnx/xil_ans_printfriendly.jsp?getPagePath=18429&BV_SessionID=@@@@0542910990.1127879856@@@@&BV_EngineID=ccccaddfkjkfkhdcefeceihdffhdfjf.0
For 1 see the link above!

here goes example for 2..........

Code:

module test();
integer i;
initial i=0;
// Print 0 to 100
initial begin
begin : my_block // <-- this is the my_block we will disable
while(1) begin // infinite while loop
if (i>100)
disable my_block;
else
$display("%d",i);
i=i+1;
end
end
end
endmodule // test

Hope this helps!

Matrix_YL

Joined: 19 Aug 2005
Posts: 107
Helped: 2

28 Sep 2005 6:27 limit iterations in loop vba

Thanks

Quote:

2.While loops can have Disable statements. The Disable statement must be use inside a labeled block, since the syntax is "disable<blockname>."

By the way ,The 2 always be used to testbench module ?

nand_gates

Joined: 19 Jul 2004
Posts: 907
Helped: 120

29 Sep 2005 5:29 loop_iteration_limit en vhdl

This is the code for count leading zero's in input byte!!

Code:

module test(din, cnt);
input [7:0] din;
output [3:0] cnt;
reg [3:0] cnt;
always @(/-*AS*-/din) begin
cnt = 0;
begin : my_block // <-- this is the my_block we will disable
integer i;
i=7;
while(i >= 0) begin // infinite while loop
if (din[i] == 1'b1)
disable my_block;
else
cnt = cnt + 1;
i=i-1;
end
end
end
endmodule // test

You can use it in synthesizable code but not recomended!!!