Yes, the transceiver CMU PLL may fail to lock on Stratix® IV GX/GT, HardCopy® IV GX, and Arria® II GX/GZ devices after CMU PLL dynamic configuration in the following specific corner case.
- Using non-dedicated REFCLK pins to clock the CMU PLL
- REFCLK pins from outside the transceiver block via an ITB line
- Clock output ports from left/right GPLLs (PLL cascading)
- Dedicated CLK input pins through GCLK network
- Hard-wiring the ALTGX_RECONFIG MegaWizard® reconfig_mode_sel port to a fixed value of 3'b100 (CMU PLL reconfiguration mode).
This problem is not seen in simulation.
This problem is present in all Quartus® II software versions up to and including Quartus II 10.1.
To correct this problem you must install Quartus II software version 10-1-SP1, and regenerate your ALTGX_RECONFIG Megawizard component.