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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

No content int the on-chip memory in simulation ?

Here is my problem.

I have done a little processor in verilog.

I have create a new SOPC component for it and i connect it to an onchip memory.

With my de2, i have a good behaviour.

I can see that by SignalTap : On reading the memory, data come back from the memory on the readdata.

The onchip has been initialized with "memory content editor"

With ModelSim,

- I generate the SOPC system with support for simulation,

- I launch the simulation

The problem :

In reading the memory, no data come back from the memory on the readdata port, in the wave window.

I suppose it is a problem with the memory initialisation with ModelSim.

I have written some information in the generated .dat file ( in <sopc_name>_sim/<memory_name>.dat ). I have tried different format :

- lines of 8 hexadecimals :

00000000

08000001

- hexadicimal format like this :

:10000000241000002411000024121000261000010A

:100010003C010001342186A0120100030000000011

:100020000800000300000000241000002631000139

:10003000AC111000080000030000000000000000E8

:00000001FF

- hexadecimal format like this

:0400000000000000FC

:0400010024110000C6

:0400020008000004EE

:0400030000000000F9

:0400040000000000F8

But no data came back from the onchip in the simulation.

There is no error.

I hope i am explicit enough.

Any suggestion ?

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Maybe one hint :

    In ModelSim it is possible to modify the content of the onchip memory.

    In the top bar, select

    View - Memory List

    Double click on the memory instance you want to edit the content.

    Right click on the memory content to import data in memory.

    But the file has to have a .mem file extention.

    So now, i only try to manually edit the content of the memory and it works in simulation in the wave window. Continue to search ...
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Another problem one step further.

    I am able to load memory content.

    .mem files can content lines of 8 hexadecimals like this

    24100000

    24110000

    3C010001

    342186A0

    12010003

    00000000

    ...

    Problem :

    But when i run the simulation by run 1000 ns, hop all the memory is reinitialised with 0 everywhere.

    It seems that it is a modelsim problem but maybe it is a problem du to the previous SOPC generated .do files.