Why does my fractional PLL with the reconfiguration feature enabled fail to lock in Stratix V devices?

Description

Due to a problem in Quartus® II versions 11.1SP2 and earlier, fractional PLLs implemented with the Altera® PLL IP and attached Altera PLL reconfig IP may fail to lock when implemented in certain locations on Stratix® V devices. 

An additional symptom is that the mgmt_waitrequest signal is always asserted.

Resolution

If PLLs with reconfiguration are used on Stratix V devices, use version 12.0 or later of the Quartus II software.