Answers Database


M1.3/M1.4 PAR/MAP: TBUFs with RLOC Constraint Must be Part of RPM with RLOC_ORIGIN Constraint


Record #1861

Product Family: Software

Product Line: FPGA Implementation

Product Part: map

Product Version: 1.4.

Problem Title:
M1.3/M1.4 PAR/MAP: TBUFs with RLOC Constraint Must be Part of RPM with RLOC_ORIGIN Constraint



Problem Description:
Urgency: standard

General Description:
TBUFs with RLOC constraints must be part of an RPM with an RLOC_ORIGIN Constraint.

Platform(s) affected: All
Architecture(s): All
Design Step(s): MAP, PAR
Reference Number: 12181, 18283


Solution 1:

The problem here is that TBUF RPMs are not supported.
TBUFs can only be constrained using explicit locations
specified either on a schematic, or UCF constraints file.

As a result, if you attach an RLOC constraint to a TBUF in
your design, the RPM containing the TBUF must also have an
RLOC_ORIGIN constraint attached to it so that the RLOC can
be resolved to an explicit location. If the RPM does not
have an attached RLOC_ORIGIN constraint, you will see the
following error in Map:

<input> ERROR:baste:199 - RPM "hset" contains three-state
    elements but has no RLOC_ORIGIN. RPMs with three-state
    elements must be fixed to an exact die location.
</input>


Example:

    You must either specify an location
    constraint specifying an explicit location to a TBUF:



     ----+
	 |
       |\|   LOC = TBUF_R3C5.1
   ____| \______
       | /
       |/


     Or specify an RLOC (relative location) in conjunction
     with an RLOC_ORIGIN constraint specifying the reference
     location for TBUF. In the example below, the origin
     has been specified as R0C0 (row0, col0), which taken
     in conjunction with the RLOC of TBUF_R1C1.1, resolves
     to an explicit location of TBUF_R3C5.1:

     ----+   RLOC = TBUF_R1C2.1
	 |
       |\|   RLOC_ORIGIN = R2C3
   ____| \______
        | /
        |/


    UCF file example:
    -----------------
    INST /DESIGN1/GROUPS/BUF1 LOC=TBUF_R3C5.1 ;

    Here "/DESIGN1/GROUPS/BUF1" is the name of the TBUF.



Solution 2:

You may alternatively constrain the wide decoders using
edge constraints T, B, L, or R for top, bottom, left, or
right edges.




End of Record #1861 - Last Modified: 08/13/98 18:49

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