CELL halfadder_8 {
  CELLTYPE = block ;
  ATTRIBUTE { adder }
  PIN [7:0] a_in {
    DIRECTION = input ;
  }
  PIN [7:0] out {
    DIRECTION = output ;
  }
  FUNCTION {
    BEHAVIOR {
      out = a_in + c_in ;
    }
  }
  TEMPLATE carry_propagate {
    GROUP low_bits { 0 : <high_bit> }
    VECTOR ( ?! a_in[low_bits] -> ?! out[<high_bit>] ) {
      ENERGY = 1 ;
    }
  }
  carry_propagate = dynamic {
    high_bit = 7 ;
  }
  carry_propagate = dynamic {
    high_bit = 6 ;
  }
  carry_propagate = dynamic {
    high_bit = 5 ;
  }
  carry_propagate = dynamic {
    high_bit = 4 ;
  }
  carry_propagate = dynamic {
    high_bit = 3 ;
  }
  carry_propagate = dynamic {
    high_bit = 2 ;
  }
  carry_propagate = dynamic {
    high_bit = 1 ;
  }
  carry_propagate = dynamic {
    high_bit = 0 ;
  }
} // end CELL halfadder_8