Nios® V Embedded Processor Design Handbook

ID 726952
Date 7/16/2025
Public

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Ixiasoft

Document Table of Contents

2.3.1.4.3. Defining Address Span Extender Linker Memory Device

  1. Define the Address Span Extender (EMIF) as the reset vector. Alternatively, you can assign the Nios® V processor reset vector to other memories, such as OCRAM or flash devices.
    Figure 17. Multiple Options as Reset Vector

    However, the Board Support Package (BSP) Editor cannot automatically register the Address Span Extender (EMIF) as a valid memory. Depending on the choice you made, you see two different situations as shown in the following figures.

    Figure 18. BSP Error when Defining Address Span Extender (EMIF) as Reset Vector
    Figure 19. Missing EMIF when Defining Other Memories as Reset Vector
  2. You must manually add the Address Span Extender (EMIF) using Add Memory Device, Add Linker Memory Region, and Add Linker Section Mappings in the BSP Linker Script tab.
  3. Follow these steps:
    1. Determine the address span of the Address Span Extender using the Memory Map (The example in the following figure uses Address Span Extender range from 0x0 to 0x3fff_ffff).
      Figure 20. Memory Map
    2. Click Add Memory Device, and fill in based on the information in your design’s Memory Map:
      1. Device Name: emif_ddr4.
        Note: Ensure you copy the same name from Memory Map.
      2. Base Address: 0x0
      3. Size: 0x40000000
    3. Click Add to add a new linker memory region:
      Table 22.  Adding Linker Memory Region
      Steps Reset Vector
      emif_ddr4 Other memories
      1

      Add a new Linker Memory Region called reset.

      • Region Name: reset
      • Region Size: 0x20
      • Memory Device: emif_ddr4
      • Memory Offset: 0x0

      Add a new Linker Memory Region for the emif_ddr4.

      • Region Name: emif_ddr4
      • Region Size: 0x40000000
      • Memory Device: emif_ddr4
      • Memory Offset: 0x0
      2

      Add a new Linker Memory Region for the remaining emif_ddr4.

      • Region Name: emif_ddr4
      • Region Size: 0x3fffffe0
      • Memory Device: emif_ddr4
      • Memory Offset: 0x20
       
      Figure 21. Linker Region when Defining Address Span Extender (EMIF) as Reset Vector
      Figure 22. Linker Region when Defining Other Memories as Reset Vector
    4. Once the emif_ddr4 is added to the BSP, you can select it for any Linker Section.
      Figure 23. Added Address Span Extender (EMIF) Successfully
    5. Ignore the warning about Memory device emif_ddr4 is not visible in the SOPC design.
    6. Proceed to Generate BSP.