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M1.2/M1.3/M1.4 MAP: "place instance *" constraint causes ERROR:x4kma:148 - IBUF symbol cannot be merged, incompatible site types


Record #2337

Product Family:  Software

Product Line:  Merged Core

Problem Title:
M1.2/M1.3/M1.4 MAP:  "place instance *" constraint causes
ERROR:x4kma:148 - IBUF symbol cannot be merged, incompatible site types



Problem Description:
Keywords:  constraint, place, instance, x4kma, merge,
incompatible site types, wildcard, *

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:

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