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AR# 13047

4.1i Spartan-XL PAR - Routing continues for many iterations after timing is met

Description

Keywords: routing, routed, timing, score, 0, zero

Urgency: Standard

General Description:
My router continues long after the design was successfully routed and timing constraints were met.

Solution

1

This problem is fixed in the latest 4.2i Service Pack, available at:
http://support.xilinx.com/support/techsup/sw_updates.
The first service pack containing the fix is 4.2i Service Pack 1.

2

The problem is caused by a bug related to offset constraints in the timing analysis tools.

Another way to work around the problem is to place a limit on the number of router iterations to be attempted:

In Foundation:
Go to Implementation --> Options --> Implementation Options -->Place and Route tab; then, define the routing passes to be anything other than "Auto".

In ISE:
Right-click on Implement Design -->Properties --> Place and Route tab; then, give a value to the Routing Passes dialog box.

In the command line:
Add the switch "-i n", where "n" is the number of router iterations to be run.
AR# 13047
Date Created 08/29/2007
Last Updated 10/20/2008
Status Archive
Type General Article