Answers Database
2.1i Floorplanner: It writes out bad constraints for BEL PAD
Record #6319
Product Family: Software
Product Line: Merged Core
Product Part: Floorplanner
Problem Title:
2.1i Floorplanner: It writes out bad constraints for BEL PAD
Problem Description:
Urgency: Standard
General Description:
After running the command "Constrain from Placement" or
placement of the BUFG in the Floorplanner GUI,and then
run map, the following error may occur:
Verifying F/HMAP validity based on pre-trimmed logic...
ERROR:OldMap:563 - Bel type "PAD" is not supported.
ERROR:OldMap:563 - Bel type "PAD" is not supported.
Or
ERROR:OldMap:532 - Unable to obey design constraints
which require the combination of the following symbols
into a single CLB:
DFF symbol "U1/mux_sel_reg<2>" (output
signal=S<2>)
No function generator is available.
These symbols share the same LOC parameter.
Solution 1:
A working around is to constrain the pad driving the BUFG to
a location that will force PAR to use the BUFG location that
is closes to the pad.
OR
The cause of the problem is that the corresponding FG record in
the mfp file has not suffixes, and the default for map is to put
the FG records, into F/G Lut, not the H Lut. This is only a
problem, when the H Lut is not in a RPM. The workaround is
to modify the mfp file by converting the troublesome FG
records to FGH.
This will be fixed in the service pack.
http://support.xilinx.com/support/techsup/sw_updates/
End of Record #6319 - Last Modified: 01/03/00 08:04 |
