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AR# 41721

MIG Spartan-6 MCB DDR3 SDRAM - Is the "OUT_TERM = UNTUNED_50" UCF constraint supported for MCB designs?

Description

Is the "OUT_TERM = UNTUNED_50" UCF constraint supported forSpartan-6 MCB designs?

If so, what is the recommended pinout?

Solution

The "OUT_TERM = UNTUNED_50" constraint is supported for Spartan-6 MCB designsand has been tested and verified at the maximum supporteddatarate (800 Mb/s) for DDR3. The recommended UCF settings to support this are shown below:

NET "mcbx_dram_dq[*]" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_addr[*]" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_ba[*]" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_dqs" IOSTANDARD = DIFF_SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_udqs"IOSTANDARD = DIFF_SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_dqs_n"IOSTANDARD = DIFF_SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_udqs_n" IOSTANDARD = DIFF_SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_clk"IOSTANDARD = DIFF_SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_clk_n" IOSTANDARD = DIFF_SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_cke"IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_ras"IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_cas" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_we" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_odt" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_ldm" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_udm" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_dram_ddr3_rst" IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_rzq"IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;
NET "mcbx_zio"IOSTANDARD = SSTL15_II | OUT_TERM = UNTUNED_50;

Assigningthe "OUT_TERM = UNTUNED_50" constrainton select outputs only is not recommended as it affects timing with respect to the other outputs and has not been tested.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
40778 MIG Spartan-6 MCB - Termination and I/O Standard Guidelines N/A N/A

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
40778 MIG Spartan-6 MCB - Termination and I/O Standard Guidelines N/A N/A
AR# 41721
Date Created 05/06/2011
Last Updated 12/15/2012
Status Active
Type General Article
Devices
  • Spartan-6 LX
  • Spartan-6 LXT
IP
  • MIG