Why need specify Memory initialization file for running Nios ii in Modelsim

[Altera_Forum]

Hi, I am new on simulation using Modelsim. According to altera Quartus software handbook (under the section running Nios ii system with modelsim), the document stated that " to run a Qsys generated Nios ii system with modelsim, you must first create a simulation model and testbench and specify memory initialization file". Anyone knows why we need to specify a memory initialization file?

[Altera_Forum]

You are simulating a processor, this is the code that the simulated processor is running.

[Altera_Forum]

Thanks for the information Galfonz.  

Between, for example, I wish to run the simple hello word program. Is it mean that the memory initialization file helps to put the code into the memory so that the processor is able to process the hello world.c?

[Altera_Forum]

Maybe should rephase a little bit. The mcu or processor can not run with out a memory. And during mcu start up. It will going to look for file for all kind of initialization where this store in a memory. And conrtol by progam counter.

[Altera_Forum]

Typically your NIOS code will reside in an on-chip memory. You set the processor reset and interrupt addresses to be in that on-chip memory. I'd recommend an LED blink program rather than hello, world as it's easier to verify your results. Follow a tutorial that blinks LEDs. I don't think a console will work in simulation other than seeing logic levels of the RS232 wire. There is a utility somewhere that you will need to run to convert your software binary to mif format for use in the sim. Sorry but I don't remember what it is called.

[Altera_Forum]

Thanks all! 

That mean if I did not specify memory initialization file, the on-chip memory would be empty and the processor is running with no data available? While on the other hand if there is an memory initialization file, the on-chip memory would contain the software code for the processor to process?

[Altera_Forum]

you are right...