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AR# 35828

ISE 10.1 SP3 Spartan IIE MAP - "ERROR:Pack:1107" on GCLK IOBs


When I add a PULLDOWN constraint to the GCLK clock pin in the UCF in a design targeting a Spartan IIE device, the following error is received during MAP.

ERROR:Pack:1107 - Unable to combine the following symbols into a single GCLKIOB  component:
    PAD symbol "local_32m" (Pad Signal = local_32m)
    PULL symbol "local_32m_PULLDOWN" (Output Signal = local_32m)
    GCLKIBUF symbol "local_32m_u" (Output Signal = local_32m_t)
   Symbol local_32m_PULLDOWN is not a kind of symbol that can join a clock I/O  component.

 How can I solve this issue?


The GCLK is an input only pin in Spartan IIE devices and does not have optimal pull-up/pull-down resistors.

To resolve this problem, remove the PULLDOWN constraint.
For more information, please refer to the Spartan IIE Date sheet.

AR# 35828
Date Created 05/24/2010
Last Updated 07/29/2014
Status Active
Type General Article
  • Spartan-IIE
  • ChipScope Pro - 9.2i
  • ChipScope Pro - 9.2i sp1
  • ChipScope Pro - 9.2i sp2
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  • ChipScope Pro - 9.2i sp3
  • ChipScope Pro - 9.2i sp4
  • ChipScope Pro - 10.1
  • ChipScope Pro - 10.1 sp1
  • ChipScope Pro - 10.1 sp2
  • ChipScope Pro - 10.1 sp3
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