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AR# 15995

5.1i Floorplanner - "Unable to find sym <inst>" appears when cross-probing from Timing Analyzer fails to locate a component


Keywords: Floorplanner, Timing Analyzer, cross-probing, unable, find

Urgency: Standard

General Description:
Cross-probing from Timing Analyzer to Floorplanner fails to locate certain components or signals, and a message reports "unable to find sym <instance name>". However, these signals and components appear in FPGA Editor.


For designs that contain wide-LUT functions (FG5/FG6/FG7, etc...) or carry-chained logic (CY), components are merged from different slice locations to make up the wide-function representation in Floorplanner.

This problem is fixed in the latest 5.1i Service Pack, available at:
The first service pack containing the fix is 5.1i Service Pack 3.

Please see (Xilinx Answer 15994) for information on other possible causes of this problem.
AR# 15995
Date Created 10/24/2002
Last Updated 03/06/2005
Status Archive
Type General Article