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AR# 30005

10.1 EDK, MPMC v4.00.a - ERROR:Pack:946 - The I/O component "ddr2_ddr_clk_o" has an illegal IOSTANDARD


When implementing a Spartan-3 MPMC design, I receive the following error:

"ERROR:Pack:946 - The I/O component "ddr2_ddr_clk_o" has an illegal IOSTANDARD

value. Components of type DIFFM do not support IOSTANDARD SSTL18_II. Please

correct the IOSTANDARD property value."

It does not occur for Spartan-3A, Spartan-3E, or Spartan-3DSP devices. How do I resolve this error?


This error is caused by the base Spartan-3 device family not supporting DIFF_SSTL18_II outputs, which the MPMC uses.

A work-around to this issue is to modify the MPMC to use two OBUFs, each with the supported SSTL18_II I/O standard. Copy the MPMC Core from the EDK repository, and change the differential outputs to single OBUFs.

For MIG-based MPMC PHYs:

This issue has been fixed, starting with MPMC v4.00.a, released in EDK 10.1.

For the MPMC Static PHY:

Xilinx plans to fix this issue in the newest core released in EDK 11.1.

AR# 30005
Date Created 01/03/2008
Last Updated 12/15/2012
Status Active
Type General Article