Nios® V/II Embedded Design Suite (EDS)
Support for Embedded Development Tools, Processors (SoCs and Nios® V/II processor), Embedded Development Suites (EDSs), Boot and Configuration, Operating Systems, C and C++
12621 Discussions

Is On-Chip Memory Size Configurable on the NIOS II?

New Contributor I

Like the title says, wondering if on-chip memory size can be configured in software.


For example, my current project has an on chip memory size of ~131KB. Is it possible to increase this amount to say, ~256Kb?


Thanks in advance!

0 Kudos
2 Replies

Hi Neil!

First of all, thank you for reaching us. I'm Eliath Guzman.

unfortunately, there is not a way to change the memory size by software.

This is because when you are creating the project and defining the parameter on Platform Designer before going to Nios II, you must indicate the size of the memory you need. Each device has a maximum possible size, it depends on the number of regions available for this proposal in the FPGA.


So... to do this follow the next steps:

  1. From the Qsys library pick list, look inside the Memories and Memory Controllers --> On-Chip folder and select On-Chip Memory ( RAM or ROM) then, click Add.
  2. Configure the memory :
  • Set the memory width to ... ( could be 4-8-16-32 bits, depends on your requirements)
    • Set the Total Memory Size to .... the size you need, in this case, you mentioned that a 256Kb is needed.
    • Set the Dual-Port Access to Enabled
    • Click Finish

You also could consult this document.

If you need more information about how On-chip memory works, consult this link


Please, let me know if there's something else I can do for you or if you have any questions about the answer above.




0 Kudos

Hi Neil!

I was wondering if the information I shared with you was useful to solve your issue!

Please let me know if I can do anything else for you or if I could close the case, it is important to mention that after moving the case to 'close' you have a period of 15 days to make a comment and it automatically will be open again.



-Eliath Guzman


0 Kudos