You may receive this message in the Quartus® II software version 5.1 if your design includes memory placed in Cyclone® II M4K memory blocks

You may receive this message in the Quartus^® II software version 5.1 if your design includes memory placed in Cyclone® II M4K memory blocks. The error message applies to various memory configurations which are documented in the Cyclone II FPGA Family Errata Sheet (PDF). Refer to the errata sheet for a description of the workarounds, and how to determine if your devices are affected by this problem.

You may also receive the below error message if your design targetting a Cyclone II device includes memory blocks with In-System Memory Content Editor enabled. The In-System Memory Content Editor feature is not supported with any memories placed in the Cyclone II M4K blocks in affected devices.

To disable the In-System Memory Content Editor feature, for each memory, turn off the Allow In-System Memory Content Editor to capture and update content independently of the system clock option in the MegaWizard Plug-In Manager. An alternative method is to modify the variation wrapper file by editing ENABLE_RUNTIME_MOD to NO in the lpm_hint parameter or generic. For example, ENABLE_RUNTIME_MOD=NO.

To enable full functionality of the M4K memory blocks, you must target fixed revision silicon devices. Refer to the errata sheet for details on how to target fixed revision silicon devices.

Error Message:

Error: Implementation of M4K memory block WYSIWYG primitive "<>" of altsyncram megafunction may not work with current target device family. To make this implementation compatible with target device family, at the expense of area and speed, set the value of CYCLONEII_SAFE_WRITE parameter to RESTRUCTURE. Please refer to the Cyclone II FPGA Family Errata Sheet for more information on this feature.