When using memories wider than 32 bits for code storage, your simulation may fail due to the memory '.dat' file being creating incorrectly. This failure will cause unknown instructions to be fetched by the Nios® II instruction master during functional simulation.
A patch has been created for Nios II Embedded Design Suite (EDS) version 7.1 SP1.
The patch files can be download from the Altera® FTP site from the following URLs:
PC-NIOS_II-7.1_SP1-1.02-README.txt
You can also contact Altera Applications at mySupport and request patch 1.02 for the Nios II EDS version 7.1 SP1 to correct this problem. Note this patch only works with Nios II EDS version 7.1 SP1.