Forum Discussion

KLohr's avatar
KLohr
Icon for Occasional Contributor rankOccasional Contributor
6 years ago

How do you initialize a ROM for simulation?

I am using a 1-Port ROM in a max 10 device. When I configured the IP I selected and generated an intel hex file for memory content data. But during simulation the values are all 0. Is there a way to initialize a ROM for simulation like we do for UFM?

3 Replies

  • IDeyn's avatar
    IDeyn
    Icon for Contributor rankContributor
    6 years ago

    Hi KLohr!

    First of all, I would like to recommend using *.mif file instead of hex file for simulation of initial content in ROM.

    Hope that helps.

    --

    Best regards,

    Ivan

    • KLohr's avatar
      KLohr
      Icon for Occasional Contributor rankOccasional Contributor
      6 years ago

      OK, so I switched to using *.mif file and I still get all 0's in my simulation. Any further ideas? The ROM .v file has the following line in it. But it doesn't seem to be looking at it:

      altsyncram_component.init_file = "lookuptable.mif",

  • Abe's avatar
    Abe
    Icon for Frequent Contributor rankFrequent Contributor
    6 years ago

    Are you using the tool generated compile/simulation script - msim_setup.tcl ? If not, then copy the hex/mif file to the simulation directory from where you invoke modelsim and then run the simulation.

    If using the msim_setup.tcl script, there's a section in the script that does the file copy for all memory init files.. you will have to include your ROM hex/mif file in that section and then start the compile/simulation using that script.

    Here's what the file copy part of script looks like (msim_setup.tcl) 

    alias file_copy {
  echo "\[exec\] file_copy"
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_ociram_default_contents.dat ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_ociram_default_contents.hex ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_ociram_default_contents.mif ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_rf_ram_a.dat ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_rf_ram_a.hex ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_rf_ram_a.mif ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_rf_ram_b.dat ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_rf_ram_b.hex ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_nios_cpu_cpu_rf_ram_b.mif ./
  file copy -force $QSYS_SIMDIR/submodules/nios_timer_system_system_RAM.hex ./
}

    The last line in that is what I added in after generating the NIOS SW code that resides in the on-chip RAM. What this line does is copy the generated hex file to the simulation folder from where the simulator can pick it up during simulation.