Answers Database
1.5i, 2.1i Map - "place instance *" constraint causes ERROR:x4kma:148 - IBUF symbol cannot be merged, incompatible site types
Record #2337
Product Family: Software
Product Line: FPGA Implementation
Product Part: map
Product Version: 1.5i
Problem Title:
1.5i, 2.1i Map - "place instance *" constraint causes ERROR:x4kma:148 - IBUF symbol cannot
be merged, incompatible site types
Problem Description:
Urgency: standard
General Description:
Map prints out the following three errors, each related to
the same problem (your signal names will vary):
<OUTPUT>
Verifying F/HMAP validity based on pre-trimmed logic...
Removing unused logic...
Processing global clock buffers...
ERROR:x4kma:148 - IBUF symbol `$1I89' (output
signal=RESET_NET) cannot be merged into I/O "RESET".
The two symbols have incompatible site types (e.g,
one may be a flip-flop and the other a LUT).
ERROR:x4kma:175 - IBUF symbol `$1I89' (output
signal=RESET_NET) cannot be placed into IOB "RESET". You
may be attempting to put more resources into
this IOB than it can support. Please see the Xilinx
Programmable Logic Data Book for information on the IOB
structure of the target device.
ERROR:x4kma:157 - OBUF symbol `$1I56' (output signal=Q_PAD8)
cannot be combined into I/O "Q_PAD8". The two symbols
have incompatible site types (e.g, one may be a flip-flop
and the other a LUT)..
</OUTPUT>
Solution 1:
In the case of CLB constraints applied to hierarchys, the work around is to remove
all I/O from the hierarch and place it at the top level.
Solution 2:
What has happened is that Map has expanded the "*" wildcard
in the following placement constraint to include both IOBs as
well as CLBs in the set of elements constrained by the
statement,
place instance *:[clb_r2c1 clb_r10c3]
and tries to map both CLB and IOB components into the
specified area.
Map does not recognize that the PLACE INSTANCE constraints
in the example are intrinsically CLB-specific constraints.
The only workaround is to narrow down the set of instances
referenced by the constraint to nets or blocks associated only
with CLBs. It may be possible to do this by using part of an
appropriate shared name string with the "*" wildcard symbol.
The alternative is to specify the constraints on a per-CLB
basis.
Bug Reference #: 17298
R_Stm, KL
End of Record #2337 - Last Modified: 06/26/99 16:15 |
