ship: Alu1

== Ports ===========================================================
data  in:   in
data  in:   inOp

data  out:  out

== Constants ========================================================
NEG:
INC:
DEC:
ABS:

== TeX ==============================================================
== Fleeterpreter ====================================================
    public void service() {
        if (box_in.dataReadyForShip() && box_inOp.dataReadyForShip()) {
            int data   = box_in.removeDataForShip();
            int opcode = box_inOp.removeDataForShip();
            switch(opcode) {
                case 0: box_out.addDataFromShip(-1 * data);      // NEG
                    break;
                case 1: box_out.addDataFromShip(data+1);         // INC
                    break;
                case 2: box_out.addDataFromShip(data-1);         // DEC
                    break;
                case 3: box_out.addDataFromShip(Math.abs(data)); // ABS
                    break;
                default: box_out.addDataFromShip(0);
                    break;
            }
        }
    }

== FleetSim ==============================================================
== FPGA ==============================================================
  reg                    have_a;
  reg [(`DATAWIDTH-1):0] reg_a;
  reg                    have_op;
  reg [(`DATAWIDTH-1):0] reg_op;

  always @(posedge clk) begin
    if (!have_a) begin
      `onread(in_r, in_a) have_a = 1; reg_a = in_d; end
      end
    if (!have_op) begin
      `onread(inOp_r, inOp_a) have_op = 1; reg_op = inOp_d; end
      end
  
    if (have_a && have_op) begin
      case (reg_op)
        0: out_d = -reg_a;
        1: out_d = reg_a+1;
        2: out_d = reg_a-1;
        3: out_d = (reg_a<0) ? (-reg_a) : reg_a;
        4: out_d = 37'b1111111111111111111111111111111111111;
        default: out_d = 0;
      endcase        
      `onwrite(out_r, out_a)
        have_a  = 0;
        have_op = 0;
      end
    end
  end


== Contributors =========================================================
Adam Megacz <megacz@cs.berkeley.edu>