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Lot of reserved memory in dspic30f

Discussion in 'Microcontrollers' started by elecLear78, Jun 5, 2017.

  1. elecLear78

    elecLear78 Member

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    I was studying about the memory of the dpsic30f family microchip. In general also i am finding that there is lot of reserved memory why is it so? Is it a kind of wastage or they are not able to use it? I don't understand this.
     
  2. misterT

    misterT Well-Known Member Most Helpful Member

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    I bet it is used for something if it is reserved. Where is this memory area that is reserved? Is it sram or flash? Usually part of the sram is reserved for peripheral registers etc. Then the freely usable memory space comes after that. Do you have a datasheet page where you found this information you are referring to? Is there some sort of memory that is not accessible?

    Modern microcontroller memories are designed for C programming language. You can easily map C-structures directly to peripheral registers etc. Even the instruction sets are designed for C compilers.
     
    Last edited: Jun 5, 2017
  3. hexreader

    hexreader Member

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    Only the memory SPACE is reserved. No physical memory exists for these locations.

    My guess is that these reserved addresses may be for current, or possible future PICs with more memory and more registers.

    No physical memory is being wasted.
     
  4. dave

    Dave New Member

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  5. misterT

    misterT Well-Known Member Most Helpful Member

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    Ok. I get it. When they design a peripheral, they need to assign registers to control the peripheral. It is smart to leave some gaps between different peripheral register for future use. If they need to add some functionality, they can use the unused memory near the existing registers and they do not need to move around and mess with registers assigned to other peripherals.
     
  6. elecLear78

    elecLear78 Member

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    If you see the below memory we see lot of reserved. why is it like that? memory.png
     
  7. elecLear78

    elecLear78 Member

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    I did not understand this you mean to say that they will not actually insert any physical chip in these memory locations. Am i correct?
     
  8. hexreader

    hexreader Member

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    You are correct.
     
  9. elecLear78

    elecLear78 Member

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    Ok thank you very much. Understood.
     

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