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AR# 37483

14.x Constraints - Does the feedback constraint affect the DCM/PLL/MMCM compensation?

Description

Does the feedback constraint affect the DCM/MMCM/PLL compensation? Does the value specified in feedback constraint change the DCM/PLL/MMCM configuration?

"NET output_clock_net FEEDBACK = value units NET input_feedback_clock_net ;"

Solution

The feedback constraintis used to define the external DCM/PLL/MMCM feedback path delay so that the timing tools canproperly determine theDCM/PLL/MMCM phase shift. It is just used for Timing analysis. Itwill notaffect theDCM/PLL/MMCM compensation or the hardware.
AR# 37483
Date Created 05/01/2012
Last Updated 12/15/2012
Status Active
Type General Article
Tools
  • ISE - 10.1
  • ISE Design Suite - 11.1
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  • ISE Design Suite - 11.3
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  • ISE Design Suite - 13.1
  • ISE - 8.1i
  • ISE - 8.1i sp1
  • ISE - 8.1i sp2
  • ISE - 8.1i sp3
  • ISE - 8.2i
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  • ISE - 8.2i sp3
  • ISE - 9.1i
  • ISE - 9.1i sp1
  • ISE - 9.1i sp2
  • ISE - 9.1i sp3
  • ISE - 9.2i
  • ISE - 9.2i sp1
  • ISE - 9.2i sp2
  • ISE - 9.2i sp3
  • ISE - 9.2i sp4
  • ISE Design Suite - 12.4
  • ISE Design Suite - 13
  • ISE Design Suite - 13.2
  • ISE Design Suite - 13.3
  • ISE Design Suite - 13.4
  • ISE Design Suite - 14.1
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