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AR# 19850

7.1i Floorplanner - "ERROR:Pack:679 - Unable to obey design constraints" when trying to create RPM (replace all with placement)

Description

Keywords: MAP, 6.2i

Urgency: Standard

General Description:
I am trying to use Floorplanner to create an RPM. I run the design through the tools and open up Floorplanner after PAR. I use the Floorplanner tool "Replace All with Placement" to take advantage of the work PAR already did. However, when I write the constraints out to create the RPM, instantiate the RPM in my top level, and rerun the tools, the following error(s) occur in MAP:

"ERROR:Pack:679 - Unable to obey design constraints (MACRONAME=u0/hset,
RLOC=X37Y8) which require the combination of the following symbols into a
single SLICE component:
MUXCY symbol "u0/u0/BU30" (Output Signal = u0/u0/N2029)
FLOP symbol "u0/u0/BU33" (Output Signal = u0/u0/N21)
MUXCY symbol "u0/u0/BU36" (Output Signal = u0/u0/N2034)
XORCY symbol "u0/u0/BU37" (Output Signal = u0/u0/N2018)
LUT symbol "u0/u0/BU29" (Output Signal = u0/u0/N2027)
FLOP symbol "u0/u0/BU39" (Output Signal = u0/u0/N20)
XORCY symbol "u0/u0/BU403" (Output Signal = u0/u0/N4550)
The XORCY symbol u0/u0/BU403 is unable to be placed in either XORF or XORG
sites. Please correct the design constraints accordingly.
ERROR:Pack:679 - Unable to obey design constraints (MACRONAME=u0/hset,
RLOC=X37Y8) which require the combination of the following symbols into a
single SLICE component:
MUXCY symbol "u0/u0/BU30" (Output Signal = u0/u0/N2029)
FLOP symbol "u0/u0/BU33" (Output Signal = u0/u0/N21)
MUXCY symbol "u0/u0/BU36" (Output Signal = u0/u0/N2034)
XORCY symbol "u0/u0/BU37" (Output Signal = u0/u0/N2018)
LUT symbol "u0/u0/BU29" (Output Signal = u0/u0/N2027)
FLOP symbol "u0/u0/BU39" (Output Signal = u0/u0/N20)
XORCY symbol "u0/u0/BU403" (Output Signal = u0/u0/N4550)
XORCY symbol "u0/u0/BU31" (Output Signal = u0/u0/N2017)
There are more than two XORCYs. Please correct the design constraints
accordingly."

Why cannot MAP use the same placement that was previously done?

Solution

This is a software problem in Floorplanner that causes some of the RLOC constraints to be written out incorrectly. Specifically, the XORCY constraints are invalid.

To work around this issue, remove the XORCY from the UCF, re-run NGCBuild and Rerun MAP. The tools should not complete successfully.

This will be fixed in a future release of the software.
AR# 19850
Date Created 08/23/2004
Last Updated 02/21/2007
Status Archive
Type General Article