Why an n to 2^n decoder needed

Discussion in 'Homework Help' started by glitterized_dreamz, Feb 26, 2007.

  1. glitterized_dreamz

    Thread Starter New Member

    Feb 13, 2007
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    I need a short answer for this question...Why is an "n to 2^n decoder needed for a memory using an n-bit address?
     
  2. Dave

    Retired Moderator

    Nov 17, 2003
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    Because thats how a decoder works, it converts a n-bit coded input, gives 2^n outputs where only one bit is set to 1 dependant on the input.

    Dave
     
  3. Ron H

    AAC Fanatic!

    Apr 14, 2005
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    Yes, but who ever heard of a memory that doesn't have binary-coded addressing, i.e., a memory with 1024 addressable locations would have a 10 bit address bus.
    I'm thinking this is about a memory with multiple chips, all multiplexed onto the same data bus. The decoder is needed for the chip enables. For instance, if you had 8 chips, you would need a 3-to-8 line decoder.
     
  4. Dave

    Retired Moderator

    Nov 17, 2003
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    This is pretty much what I was aiming at, however I could probably have made it clearer as to the application to memory devices - though I thought this would be clear to the OP from my original statement. Ultimately, the unique data word at the output of the decoder is utilised as the selection mechanism - i.e. providing an enable signal.

    Dave
     
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