Writing to SRAM/SDRAM on DE-2 board ?

IP controller means, you have a modul that controls your access to the memory.

it handles all your read and write access.

the ssram on the de2-70 can be like a simple ram memory setup adr & select signals or you can have burst access. sdram is indeed not that easy as mki already said. if you are going to use the sdram, you should use a ready to use sdram ip that you can focus on your application.

if your are going to use the sopc, then you can use the sdram controller ip from altera and you could also implement your application as nios executable code or write your own modul that acts like a master to gain access to your memory and does your application in hardware. or you could mix software and hardware if you use the C2H funtionality. that means part of your application are executed by nios cpu and other parts are executed by hardware.