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2.1i Virtex Map - Pack Error: MULT_AND symbol X must be connected to ...


Record #7685

Product Family: Software

Product Line: FPGA Implementation

Product Part: map

Product Version: 2.1i

Problem Title:

2.1i Virtex Map - Pack Error: MULT_AND symbol X must be connected to ...


Problem Description:
Urgency: Standard

General Description:
A case has been seen where Map got six pack errors involving MULTANDs and MUXCYs. The error message indicates that the MULTAND is not driving a MUXCY in the same slice, but this did not appear to be the true.

ERROR:xvkpu - Unable to obey design constraints (MACRONAME =
   u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/test_mult/a1/toprow,
   RLOC = R8C2.S0) which require the combination of the following symbols into a
   single slice:
      MUXCY symbol "u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU280"
	(Output Signal =   u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/N5801)
      XORCY symbol "u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU281"
	(Output Signal = u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/N331)
      MULTAND symbol "u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU283"
	(Output Signal = u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/N5816)
     MUXCY symbol "u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU284"
	(Output Signal = u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/N5800)
     XORCY symbol "u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU285"
       (Output Signal = u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/N330)
    MULTAND symbol "u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU279"
       (Output Signal = u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/N5817)
The output signal of the MULT_AND symbol u_fft/butterfly_stage0/u2_multiplier_12x12/u_test_mult/BU28
3 must be connected to the input of a MUXCY symbol
within the slice.




Solution 1:

This problem is associated with MUXCY reduction when the Select pin is stuck at 1.

A fix for this problem is scheduled for the first major release (as yet unnamed) following version 2.1i. This release is currently scheduled for March, 2000.




End of Record #7685 - Last Modified: 10/06/99 08:58

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