2. Support
  3. AR# 4567: M1.5: Constraint editor: UCF files that contain 'EXCEPT' causes Dr. Watson error or program crash
  4. AR# 45674: 13.4 and earlier - Virtex-7 and Kintex-7 - GTX IBERT core with 562.5 MHz refclk may cause map error

AR# 45674

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13.4 and earlier - Virtex-7 and Kintex-7 - GTX IBERT core with 562.5 MHz refclk may cause map error

Description

If the Virtex-7 or Kintex-7 GTX IBERT core is used under the following conditions, an implementation errorwill occur during MAP:

  • Running ISE 13.4 software and earlier
  • Using the Kintex-7 or Virtex-7 GTX IBERT core
  • Reference clock = 562.5 MHz

The following error message will occur in Map if the above conditions are met:

ERROR:PhysDesignRules:2042 - The DIVCLK_DIVIDE value 1.000000 of MMCME2_ADV instance
U_CHIPSCOPE_IBERT/U0/U_IBERT_CORE/U_USRCLK_DIVIDER_2/mmcm_adv_inst is below the Fin / Fpfd value 1.125000, where Fin
is the input frequency, 562.499930 MHz, and Fpfd min - max values of 10.000000 - 500.000000 MHz.

Solution

This issue is caused by a bug in the algorithm which determines appropriate M and D values for the MMCM used with the IBERT core to generate the USRCLKs for the GTs. For this frequency, the M and D values are set to an illegal value. At this time, a reference clock of 562.5 MHz cannot be used with the 7 series GTX IBERT core. This issue will be fixed in ISE 14.1 software.
AR# 45674
Date 05/19/2012
Status Active
Type Known Issues
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