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AR# 36270

PlanAhead - LOC error on design with MPMC


I am getting the following LOC error when I try to view a design containing a Multi-Port Memory Controller (MPMC) with PlanAhead:

ERROR: [HD-PhysicalConstraint 2] Cannot loc instance 'MCU_init/mpmc_0/mpmc_0/mpmc_core_0/gen_spartan6_mcb.s6_phy_top_if/mpmc_mcb_raw_wrapper_0/iob_clk' at site G1 found at (file = mpmc_0_wrapper.ngc, line = 29097), DP Positive pin polarity mismatch


This is a known issue with PlanAhead where PlanAhead is not correctly parsing the N side of the differential clock pair.

This error can be ignored as the MPMC is also LOCing the P side.

By LOCing the P side, PlanAhead correctly associates the N side to the Pad.
AR# 36270
Date Created 06/17/2010
Last Updated 09/30/2014
Status Active
Type Known Issues
  • Spartan-6
  • PlanAhead - 12