• adding a SDRAM controller to the NiosII core
• using a PLL core to generate a phase shifted clock for the RAM
• moving the Hello World program into the new memory and allocating a 'huge' chunk of memory

• back in Quartus II open sopc builder again
  and add an SDRAM controller (Memories and Memory Controllers/SDRAM/SDRAM Controller)
  presets: custom
  data width = 16 bits
  row width = 13
  column width = 9
  If you don't plan to pipe video or some other bandwidth hungry task through it you can leave the rest on default. The next settings in green are optional tweaks to tickle a little more performance out of the chip. (I haven't actually run benchmarks to tell if it makes any difference)
  
• under the Timing tab set CAS latency cycles to 2
  Initialization refresh cycles = 8
  Issue one refresh command every = 0.75 us
  Delay after powerup =200us
  t_rfc = 70ns
  t_rp = 20ns
  t_rcd = 20ns
  t_ac = 6.5ns
  t_wr = 14 ns
  click finish
• rename sdram_1 to sdram
• select the cpu and click edit
  set the interrupt and exception vectors to the sdram
  click finish

PLL module

System ID

• add a System ID Peripheral  (Peripherals/Debug and Performance/System ID Peripheral)
  click Finish
• rename sysid_0 to sysid

Wiring up the SDRAM chip

Eclipse ($#!*..!)

• go to your new project folder and delete the entire contents of the software subfolder
• also delete the .metadata folder in the project root (this is where the workspace is stored, among other things)
• Fire up NiosII Software Build Tools for Eclipse
• switch the workspace to your new project (File > Switch Workspace...)
  The workspace should be empty!
• right click the Project Explorer and select New > NiosII Application and BSP from Template
• under SOPC Information File name select your new DE0_NANO_SOPC.sopcinfo file
• call the project hello_sdram and leave the project template set to Hello World
• click Finish
• copy paste the code from the previous tut into the file hello_world.c
  #include <stdio.h>
  #include "system.h"
  #include "altera_avalon_pio_regs.h"
  
  int main()
  {
  
      printf("Hello from Nios II on steroids (SDRAM) !\n");
  
      int count = 0;
      int delay;
  
      while(1) {
  
  
  
          IOWR_ALTERA_AVALON_PIO_DATA(PIO_LED_BASE, count & 0x01);
  
  
  
          delay = 0;
  
          while(delay < 200000)
              delay++;
          count++;
  
      }
  
  
  
    return 0;
  }
• Note that I changed the welcome message slightly to make sure we are seeing the output of the new program
• ( If, instead of copying the previous tut, you walked through it and continued this SDRAM tut in the same folder with the same eclipse project you will have to regenerate the BSP project. Right click it and select NiosII > Generate BSP. This step is also required every time you change something about the hardware)
• select Project > Build All
• right click the hello_world project and select run as NiosII Hardware.
  The program should now blink LED0 on the DE0-Nano board and print the welcome message into the console

• open up the BSP Editor by right clicking the BSP project and selecting NiosII > BSP Editor...
  Go to the Linker Script tab and in the Linker Section Name box change every linker region from onchip_memory2 to sdram
• Add the following lines to the code:
  

#include <stdio.h>

#include <stdlib.h>

#include "system.h"

#include "altera_avalon_pio_regs.h"

int main()

{

    printf("Hello from Nios II on steroids (SDRAM) !\n");




    void *lots_of_memory = malloc(1024*1024*10); // lets allocate 10MB or memory

    printf("malloc returned 0x%08lx\n", (alt_u32)lots_of_memory);

    int count = 0;

    int delay;

    while(1) {

        IOWR_ALTERA_AVALON_PIO_DATA(PIO_LED_BASE, count & 0x01);

        delay = 0;

        while(delay < 200000)

            delay++;

        count++;

    }

  return 0;

}

• This should produce an output like this:
  malloc() returned a valid pointer to a 10MB memory block.