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AR# 34939

11.5 Virtex-6 Place - "Error Place 1223:Key-Comp-"srds/skt11_srds_rxctl/MMCM" is not placed"


When I run my Virtex-6 FPGA design through the implementation tools, MAP fails during placement with the following errors:

"ERROR:Place:1223 - Key-Comp-"srds/skt11_srds_rxctl/MMCM" is not placed.
ERROR:Place:1223 - Key-Comp-"clock/PLL_CORE/MMCM_ADV" is not placed.
ERROR:Place:1223 - Key-Comp-"srds/skt00_srds_rxctl/MMCM" is not placed.
ERROR:Place:1223 - Key-Comp-"srds/skt10_srds_rxctl/MMCM" is not placed.
ERROR:Place:1223 - Key-Comp-"clock/PLL_IO/MMCM_ADV" is not placed.
ERROR:Place:1223 - Key-Comp-"clock/PLL_FC/MMCM_ADV" is not placed.
ERROR:Place:1223 - Key-Comp-"clock/PLL_ILKN_NPU/MMCM_ADV" is not placed.
ERROR:Place:1223 - Key-Comp-"srds/skt01_srds_rxctl/MMCM" is not placed.
ERROR:Place:418 - Failed to execute IOB Placement
ERROR:Pack:1654 - The timing-driven placement phase encountered an error."

Why was MAP not able to place these components?


The "Place:1223" error can occur because of thefollowing placement restrictions, documented in the Virtex-6 Clocking Resources Guide (UG362), inthe Virtex-6 architecture:
  • If you are using a clock capable I/O to drive an MMCM, the I/O and MMCM must be in the same clock region.
  • If you are using a GT to directly drive an MMCM, the GT and MMCM must be in the same clock region (left or right).

For the known case where these errors have been seen, the root cause of the placement failure was thatthree MMCMswere competing for two site locations because of the abovetwo restrictions. The solution was to design around thishardware limitation.The placement rules are less restrictive if a GTXE drives a BUFG (GTXE -> BUFG -> MMCM.CLKIN).

A CR is under investigation to improve the error handling and provide an error message that provides more insight into the root cause of the placement failure.

AR# 34939
Date 05/19/2012
Status Active
Type Error Message
  • Virtex-6 HXT
  • Virtex-6 CXT
  • Virtex-6 LX
  • More
  • Virtex-6 LXT
  • Virtex-6 SXT
  • Less
  • ISE Design Suite - 11.2
  • ISE Design Suite - 11.3
  • ISE Design Suite - 11.4
  • ISE Design Suite - 11.5