binary subtraction arithmetic!

Discussion in 'Embedded Systems and Microcontrollers' started by Eric007, Apr 14, 2012.

  1. Eric007

    Thread Starter Senior Member

    Aug 5, 2011
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    Hello!

    Can someone show me how to do this little calculation? I'm a bit confused!

    00000 - 10011 = ?
    00000 - 00010 = ?
    00000 - 00011 = ?

    Please show me how you do the borrowing and all that!

    Thanks in advance!
     
    Last edited: Apr 15, 2012
  2. MrChips

    Moderator

    Oct 2, 2009
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    Computers do not do subtraction.
    The simplest solution is to form the 2's complement and add.
     
  3. Eric007

    Thread Starter Senior Member

    Aug 5, 2011
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    There must be a good reason why i'm asking this question...
    Actually i'm multiplying signed number using 'Booth's Algorithm'

    But yeah your " 2's complement and add" method works.
    In fact, you perform a 2's complement only on the 'signed' number then you add.

    --» 00000 - 00010 = 11110
    --» 00000 - 00011 = 11101
    --» 00000 - 10011 = 01101


    Thanks MrChips!
     
  4. t06afre

    AAC Fanatic!

    May 11, 2009
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    Try a goolge search on binary arithmetic
     
  5. bertus

    Administrator

    Apr 5, 2008
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    Eric007 likes this.
  6. Eric007

    Thread Starter Senior Member

    Aug 5, 2011
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    I did but the examples on google are too TRIVIAL and obvious but anyways I figured out how it works.

    Thanks!
     
  7. MrChips

    Moderator

    Oct 2, 2009
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    Now, see if you can alter the thread title and icon to indicate that you're done with this thread.
     
  8. chrisw1990

    Active Member

    Oct 22, 2011
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    see this thread
     
  9. Eric007

    Thread Starter Senior Member

    Aug 5, 2011
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    Is it ok now or you want me to add [SOLVED] ??
     
  10. MrChips

    Moderator

    Oct 2, 2009
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    We have to get the mods to allow the op to change the thread title, not the post title.
     
  11. chrisw1990

    Active Member

    Oct 22, 2011
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    yeh but itll do for now?
     
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