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Altera_Forum's avatar
Altera_Forum
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21 years ago

IDE New Project needs writable memory

Hello:

I'm attempting to create a second project in the Eclipse IDE

The design uses a cyclone and I've got a simple NIOS-II with real general FPGA logic function.

For memory I have a FLASH and RAM attached to the bus. I used the 'Idterface to user logic' as the module to interface to both.

When I attempy to create a project I get the message 'The SOPC does not have a writable memory device mastered by the CPUs data master.'

So my question is how best to fix this.............

THanks

George

5 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    21 years ago

    Perhaps I didn't make this clear enough.

    I've created a NIOS II project and plan to use a simple FLASH and STATIC RAM to hold the program and stack.

    I connect the FLASH and RAM using the 'interface to user logic' module in SOPC builder.

    When I try to create a new project in the ecipse IDE I get an error that there is no writable memory.

    So How do I convince the IDE that the RAM at the end of the interface to user logic is OK to use??

    Thanks

    George
  • Altera_Forum's avatar
    Altera_Forum
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    21 years ago

    It sounds as though you need to mark the memory as writable. Try setting Is_Writable = "1"; in the appropriate SYSTEM_BUILDER_INFO section of your PTF file.

  • Altera_Forum's avatar
    Altera_Forum
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    21 years ago

    In addition to what wombat states:

    Have you specified an explicit pin of avalon type "write" or "write_n" to the external SRAM? This would tell the wizard that your memory is writable (basically achieving what wombat suggests with a manual edit of the file).

    My concern is that you get your control sigaling correct so that the RAM can be physically written to in hardware. If the SRAM chip you're using has a *common* pin (rather than separate read and write inputs), write/read_n for example, I'd reccomend that you specify the 'write' pin and leave read_n out; Avalon should infer reads automatically if your master asks for an address and does not assert write.
  • Altera_Forum's avatar
    Altera_Forum
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    21 years ago

    Both good (ie. correct) answers.

    I made the write control line shared but then I also needed to select the 'Bus Interface Type' as Memory. And now I can build a new Eclipse project.

    THanks

    George
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi

    i want to create a project with nios II IDE but i have the same error like gmm can't create

    because The SOPC Builder System does not have a writable memory device mastered by the specified CPU's data master

    can any body help me thks a lots