AR# 46132

MIG 7 Series DDR3/DDR2 - Trace Matching and Derating Guidelines


The MIG 7 Series DDR3/DDR3 designs require specific trace matching guidelines be followed to ensure the target data rate be achieved. These trace matching guidelines are specified in the Design Guidelines section of the 7 Series FPGAs Memory Interface Solutions User Guide.

NOTE: This answer record is a part of the Xilinx MIG Solution Center (Xilinx Answer 34243). The Xilinx MIG Solution Center is available to address all questions related to MIG. Whether you are starting a new design with MIG or troubleshooting a problem, use the MIG Solution Center to guide you to the right information.


The trace matching requirements specified in the user guide are between:

  • Any DQ and its associated DQS/DQS#
  • Any Address and Control signal and the corresponding CK/CK#
  • CK/CK# and DQS/DQS#

The user guide specifies not only the matching requirements for maximum operation, but how much the guidelines can be loosened for slower interfaces. Refer to the user guide for specific trace matching numbers.

In general, trace lengths should be kept to less than 3 inches.

Additional Information
(Xilinx Answer 51296) Design Advisory - 7 Series Package Flight Time Changes in ISE 14.2 and Vivado 2012.2 Design Suite Releases
(Xilinx Answer 42024) 7 Series MIG DDR3 - What is the recommended trace impedance between the FPGA and the DDR3 SDRAM?
(Xilinx Answer 58873) MIG 7 Series DDR3 - Automated Trace Matching Checker against MIG 7 Series DDR3 Requirements

Revision History
08/24/12 - Initial release
01/14/14 - Added 58873



Answer Number 问答标题 问题版本 已解决问题的版本
51475 MIG 7 系列设计助手 - MIG 7 系列 DDR2/DDR3、电路板布局和设计指南 N/A N/A


AR# 46132
日期 01/14/2014
状态 Active
Type 解决方案中心