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Physical CPU Circuitry Referencing Memory

  1. Jan 19, 2012 #1
    How does a CPU send information to memory locations - physically? I know in software you can reference memory locations. I'd like to know how a CPU references them? I understand that it symbolizes a memory location using bits (00000101 = 5) but - how does that string of bits work in the circuitry to send information to a memory location?

    Let's say you want to write a byte 10101010 to a memory location signified by another byte 00001111, how would the circuitry do that?

    It would seem severely complicated for a CPU to reference so many memory locations - but CPUs handle that and I don't see how designers could possibly sit and make circuitry to reference billions of bytes. So, I am assuming there is a trick, or simple way of doing it. That's what I would like to know.
     
  2. jcsd
  3. Jan 19, 2012 #2

    phinds

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    It USED to be that the addressing logic really DID address memory in parallel the way you think it is unlikely to, but as memory sizes got larger this got to be a problem, so now it's generally done in a more complex way.

    The brute force method just resolved the address to a signal that turned on one row of a LOT of rows of memory, but now the memory is circular and the process involves a combination of address resolution and timing.

    You should be able to look all this up somewhere. I'm much too lazy to got into full detail.
     
  4. Jan 20, 2012 #3

    berkeman

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