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AR# 20005

9.1i Virtex-II MAP - RPM forcing carry chain to multiple columns leads to pack error


When I define an RPM macro to force a carry chain to multiple columns, MAP fails with the following error:

"ERROR:Pack:312 - The intersection of two collections of symbols which have restrictive placement or routing requirements encountered a problem. The two collections are:

1) A carry chain starting with carry mux "mark_adder__n0001<0>cy". Carry chains must run upwards through adjacent slices in the same column.

2) The RPM "MARK_ADDER". Relationally Placed Macros (RPMs) have a predetermined physical shape. The position of the slice containing

MUXCY symbol "mark_adder__n0001<32>cy" (Output Signal = mark_adder__n0001<32>_cyo) (RLOC=X0Y0, Set=MARK_ADDER)

MUXCY symbol "mark_adder__n0001<33>cy" (Output Signal = mark_adder__n0001<33>_cyo) (RLOC=X0Y0, Set=MARK_ADDER)

LUT symbol "mark_adder__n0001<32>lut" (Output Signal = N553) (RLOC=X0Y0, Set=MARK_ADDER)

LUT symbol "mark_adder__n0001<33>lut" (Output Signal = N557) (RLOC=X0Y0, Set=MARK_ADDER)

relative to the slice containing

MUXCY symbol "mark_adder__n0001<0>cy" (Output Signal =

mark_adder__n0001<0>_cyo) (RLOC=X1Y0, Set=MARK_ADDER)

MUXCY symbol "mark_adder__n0001<1>cy" (Output Signal =

mark_adder__n0001<1>_cyo) (RLOC=X1Y0, Set=MARK_ADDER)

LUT symbol "mark_adder__n0001<0>lut" (Output Signal = N425)



LUT symbol "mark_adder__n0001<1>lut" (Output Signal = N429)



differs in the two collections."

This problem has been determined to be a mapping bug. It has also been determined that this bug applies only to standard RPM macros; so to work around this issue, define the macro as an RPM GRID macro.


This problem is scheduled to be fixed in ISE version 10.1i Meanwhile, the problem can be avoided by using an RPM GRID macro when attempting to force a single carry chain to multiple columns.

More information about RPM GRID macros can be found at:


AR# 20005
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article