Why does the transceiver pll_locked signal deassert when rx_analogreset is asserted during simulation of Cyclone IV GX devices?

The transceiver pll_locked signal deasserts when rx_analogreset is asserted during simulation of Cyclone®  IV GX devices due to an incorrect simulation model.

The transceiver rx_analogreset signal incorrectly resets the MPLL and causes the pll_locked signal to deassert in the Quartus® II Software Version 9.1-SP2.

The following patches are available to fix this issue.

• Quartus II Software Version 9.1-SP2 Patch 2.38 for Windows
• Quartus II Software Version 9.1-SP2 Patch 2.38 for Linux
• Quartus II Software Version 9.1-SP2 Patch 2.38 Readme file  

This issue will be fixed in a future version of the Quartus II Software.