06-13-2014 10:02 AM
When I try to simulate a large generate for loop (50k) in the Vivado 2013.4, 2014.1 & 2014.2 simulators, it errors out with "loop count limit of 5000 exceeded". I tried changing the loop count in the project settings (TCL: "set_property loop_count 1000000 [current_fileset]"). That doesn't help. Any idea where the 5000 limit setting is coming from or how to change it?
The Vivado Users Guide [UG895 (v2014.1) April 2, 2014 (page 33)] notes:
Loop Count: Specifies the maximum loop iteration value. The default is 1000.
Note: The Loop Count option is used during RTL elaboration but does not apply to synthesis. For synthesis, you must specify the -loop_iteration_limit switch in the More Options field of the Synthesis Settings dialog box.
I need to synthesize this design as well with XST. Where is the synthesis and implementation limit kept also? I tried a variety of guesses as to what the more options string should be named. All failed. I don't see it documented either.
Thanks
jer
09-19-2014 03:51 AM
09-19-2014 04:30 AM
From message, it seems like the issue was to do with something like
________
module top;
genvar i;
generate
for(i = 0; i < 6000; i= i + 1)
initial $display(i);
endgenerate
endmodule
________
We had issue in vivado_simulator which has been fixed in 2014.3.