Possible Timing Failure on Certain Paths in Designs Targeting Cyclone V Devices

Description

This problem affects DDR2, DDR3, and LPDDR2 products.

External memory interfaces targeting Cyclone V devices may exhibit timing failure on paths from the following nodes to the FPGA core:

*if0|p0|umemphy|uio_pads|dq_ddio[*].ubidir_dq_dqs|altdq_dqs2_inst|input_path_gen[*].read_fifo~OUTPUT_DFF_*

Resolution

The workaround for this issue is as follows:

• Restrict the placement of core nodes to meet timing requirements.
• Compile the IP using multiple seeds and additional synthesis and fitter optimizations enabled.

This issue will be fixed in a future version.