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Need help with ALU design instructions

  1. Mar 11, 2009 #1
    1. The problem statement, all variables and given/known data


    I need to implement a "branch if greater than or equal" and a "set if less than" in my 16-bit ALU (MIPS architecture),but I'm having some difficulties with it.

    2. Relevant equations

    The "set if less than" I think,if one considers overflow,it could be implemented XOR-ing the signal bit with the overflow and then,connecting it to the less input (setting all less bits less the LSB to 0) of ALU 0,right?

    3. The attempt at a solution

    The "branch if greater than or equal" is what giving me some troubles.
    I know that a "branch if greater than or equal" is a pseudo-instruction that can be done as a slt and a beq.
    But how do I mplement that in my ALU?If the slt above mentioned is correct and considering I also have designed a beq(NOR dos bits do resultado),how do I put these 2 together in order to create a bge?

    Thanks in advance for all the help!
  2. jcsd
  3. Mar 13, 2009 #2
    I really need some help on this!
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