Quartus 5.0 and Nios Eval 5.0

The nios2-download which comes with the 5.0 kit is the first one which reads back the data it's just downloaded to check that it has been correctly written into the memories.

If you are getting this error then the data read back didn't match up with the data written. There are two possible explanations.

The first is that the elf file is incorrectly trying to initialise areas in the address map which aren&#39;t really memories. You should use `nios2-elf-readelf -S <elffile>` to find out which areas of memory are being initialised - nios2-download will write all sections containing the A flag to the target.

The second is that there is something wrong with your memories and they really aren&#39;t keeping the data which has been written into them. Clock frequencies and timing would be my first suspects here.