We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 25193

9.1i MAP/PAR - Change in the functionality for the -x switch that disables timing constraints


When I run MAP or PAR with the -x option to disable my timing constraints, I see that MAP and PAR are still timing driven. Is there any way to force the tools to run non-timing driven to minimize run time or avoid timing-impossible errors?


The meaning of the -x switch changed with ISE version 8.1i. It now causes user timing constraints to be ignored, and an auto-timespecing algorithm generates replacement timing constraints. It is possible to access the original behavior of the -x switch by using the hidden switch -ntd instead. With this switch, no timing constraints are used by MAP or PAR.

AR# 25193
Date 12/15/2012
Status Active
Type General Article