Possible Timing Closure Difficulty for QDR II Interfaces on Arria 10 Devices

Description

QDR II interfaces on Arria 10 devices may experience difficulty achieving timing closure. This problem is most evident when core-to-periphery and periphery-to-core transfers approach 333 MHz, with PLL VCO of less than 600 MHz.

Resolution

The workaround for this problem is to do one of the following:

• Try compiling with multiple seeds.
• Use a PLL VCO value of greater than 600 MHz.