WRLVL is the top-level rtl parameter that controls Write Leveling. This should be set to "ON" for ALL DDR3 designs. The MIG design always performs Write Leveling for DDR3 designs to calibrate the DQS-CK timing. RTT_WR and RTT_NOM are top-level rtl parameters that control ODT. Xilinx -灵活应变. 万物智能. 技术支持; AR# 33995: MIG 3.3, Virtex-6 FPGA DDR3 - Write Leveling does not succeed and calibration fails due to IDELAYCTRL not being automatically inferred by the software

The MIG Virtex-6 DDR2/DDR3 FPGA design goes through the following calibration stages: This series of calibration debug Answer Records focus on debugging Write Leveling, Read Leveling Stage 1, and Write Calibration / Read Leveling Stage 2. DDR Design: Write leveling for better DQ timing Share This Post Share on Twitter Share on LinkedIn Share on Facebook So far, we’ve gone through the basics of the DDR Bus , and discussed some of the Signal Integrity and timing requirements of the controller and the DRAMs. This compensates for the skew between DQS and CK and meets the tDQSS specification. Since the MIG Virtex-6 and 7 Series DDR3 design uses write leveling for all outputs (single component, multi-component, and DIMM), it is required that the board be laid out using Fly-by Topology on the clock, address, and control lines.