When using the FIR Compiler 8.1, if you want to use M9K for data and coefficient storage when targeting a Altera Cyclone® III device, you may encounter an error message saying device family Cyclone III does not support data/coefficient storage in M9K. This is due to a FIR Compiler GUI bug, which will be fixed in future releases.
To work around this problem, you can follow these steps:
1. Select device Stratix III
2. Select data storage M9K
3. Select device Cyclone III
You should now be able to properly use M9K for data and/or coefficient storage in a Cylone III device.