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AR# 66589

RLDRAM3 IP - ERROR: [Place 30-484] The packing of lutram instances into lutram capable slices could not be obeyed.


Version Found:RLDRAM3 IP v1.1

Version Resolved: See (Xilinx Answer 58435)

For certain RLDRAM3 IP UltraScale configurations. the following placer error may be seen:

[Place 30-484] The packing of lutram instances into lutram capable slices could not be obeyed.

       Number of LUTRAMs: 2944

       Number of LUTRAM capable slices required is 370 out of 9600 in the device (utilization 3.85417%)


Even though there is a sufficient number of LUTRAM capable slices in the device, the packing algorithm was not able to find a solution. Please analyze your design to determine if the number of LUTRAMs can be reduced.


If this occurs and there are sufficient LUTRAMs still available to be placed, this is likely a known issue with the Vivado Placer. To work around the Placer error, manually lock the RLDRAM3 IP logic to a PBLOCK in the same clock regions as the RLDRAM3 I/O.

This can be done by following the steps below:

  1. Open Synthesized DCP
  2. Open I/O Planner
  3. Place all memory I/O
  4. Open Device View
  5. Select the MIG module
  6. Right click and select Floorplanning => Draw Pblock
  7. Uncheck DSP48 (and RAMB18/RAMB36 if single bank memory interface)
  8. Draw the Pblock, provide the name, click OK.
    Note: Make sure that the pblock is contained in the same clock region as the memory I/O.

Revision History:

02/10/2016 - Initial Release

Linked Answer Records

Master Answer Records

AR# 66589
Date Created 02/10/2016
Last Updated 02/12/2016
Status Active
Type Known Issues
  • Kintex UltraScale
  • Virtex UltraScale
  • MIG UltraScale