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AR# 63242

MIG UltraScale - does MIG support TDQS functionality?


As per the DDR4 SDRAM Component specifications, (JESD79-4) Termination Data Strobe-TDQS_t/TDQS_c is applicable for x8 DRAMs only.

When enabled via Mode Register A11 = 1 in MR1, the DRAM will enable the same termination resistance function on TDQS_t/TDQS_c that is applied to DQS_t/DQS_c.

When disabled via mode register A11 = 0 in MR1, DM/DBI/TDQS will provide the data mask function or Data Bus Inversion depending on MR5; A11,12,10and TDQS_c is not used.

x4/x16 DRAMs must disable the TDQS function via mode register A11 = 0 in MR1.


MIG UltraScale does not support TDQS functionality and there are no plans to enable it.

TDQS_C can be left as "No Connect" and TDQS_t can be used either as DM or DBI.

Revision History:
01/07/2015 - Initial Release

Linked Answer Records

Master Answer Records

AR# 63242
Date 01/20/2015
Status Active
Type General Article
  • Kintex UltraScale
  • Virtex UltraScale
  • MIG UltraScale