DQS does not need to be LOCed to a CCIO site in the Virtex-6 design. It only needs to be LOCed to a p/n General Purpose I/O (GPIO) pair. The internally generated clocks (CPT and RSYNC) instead use clocking resources, and therefore require CCIO.
To view the PHY clocking structure for the Virtex-6 DDR2/DDR3 MIG design, see the PHY Clocking Architecture Figure in theVirtex-6 FPGA Memory Interface Solutions User Guide (UG406): http://www.xilinx.com/support/documentation/ip_documentation/ug406.pdf
For more information on the Design/Layout Guidelines for this design, please see:
Answer Number | 问答标题 | 问题版本 | 已解决问题的版本 |
---|---|---|---|
35113 | MIG Virtex-6 DDR2/DDR3 PHY - Usage of DQS | N/A | N/A |
34477 | MIG Virtex-6 DDR2/DDR3 - Capture Logic Placement Requirements | N/A | N/A |
34540 | MIG Virtex-6 DDR2/DDR3 - Resynchronization (RSYNC) logic usage and placement | N/A | N/A |
34308 | MIG Virtex-6 DDR3/DDR2 - Verify pin-out/banking requirements are met | N/A | N/A |