Description
The FIR Compiler II MegaCore function does not support back pressure mechanism, and expects the user to provide the right amount of data, according to the sampling rate set in the Mega Wizard.
Failing to do so will result in a unpredictable behavior and the core would have to be put in reset to recover its functionality.
Resolution
This will be fixed in a future version of the Altera FIR Compiler Megacore