UPGRADE YOUR BROWSER

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# 12619

4.1i Virtex-II PAR - Placer does not report Directed Placer failures.

Description

Keywords: directed, placer, placement, area, groups, range, failed

Urgency: Standard

General Description:
In 3.1i, the placer reports offending AREA_GROUP constraints if the Directed Placer fails (before attempting a "secondary" placement using a different algorithm). In 4.1i, "secondary" placement is attempted without any feedback being given to the customer to report that a constraint has caused a problem. This behavior causes excessive PAR run-time (2+ days with XC2V6000 designs).

Solution

This problem is fixed in the latest 4.1i Service Pack, available at:
http://support.xilinx.com/support/techsup/sw_updates
The first service pack containing the fix is 4.1i Service Pack 2.

This fix will enable Directed Placement failures to be reported under environment variable control:

For PCs:
set XIL_PAR_D_ERROR=1

For Workstations:
setenv XIL_PAR_D_ERROR 1

Another environment variable will cause information to be printed about any macro decomposition that occurs during placement. The
decomposition occurs when an RPM (user or internal) needs to be fitted into the device or area group range.

For PCs:
set XIL_PAR_POSTDECOMP=1

For Workstations:
setenv XIL_PAR_POSTDECOMP 1
AR# 12619
Date Created 08/29/2007
Last Updated 10/23/2008
Status Archive
Type General Article