ship: Fifo

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

data  out:  out

== Constants ========================================================

== TeX ==============================================================

The {\tt Fifo} ship is a simple fifo.  Word-sized delivered to the {\tt
in} port are enqueued into the fifo, and values which arrive at the
end of the fifo are provided to the {\tt out} port.

The internal capacity of the fifo is unspecified, but guaranteed to be
at least 16 words.

== Fleeterpreter ====================================================
    private Queue<Long> fifo = new LinkedList<Long>();
    public void service() {
        if (box_in.dataReadyForShip()) {
            fifo.add(box_in.removeDataForShip());
        }
        if (box_out.readyForDataFromShip() && fifo.size() > 0) {
            box_out.addDataFromShip(fifo.remove());
        }
    }

== FleetSim ==============================================================

== FPGA ==============================================================

  wire in0_a;
  wire out0_r;
  wire [(`DATAWIDTH-1):0] out0_d;

  fifo8 fifo8(clk, rst,
              in_r,  in0_a, in_d,
              out0_r, out_a, out0_d);

  always @(posedge clk) begin
    if (!rst) begin
      `reset
    end else begin
    in_a <= in0_a;
    out_r <= out0_r;
    out_d <= out0_d;
    end
  end

== Test =================================================================
// expected output
#expect 9

// ships required in order to run this code
#ship debug        : Debug
#ship fifo         : Fifo

debug.in:   [*] take, deliver;
fifo.in:
  literal 9;
  deliver;
  load repeat counter with 63;
  take, deliver;
  load repeat counter with 37;
  take, deliver;

fifo.out:
  load repeat counter with 63;
  take, sendto fifo.in;
  load repeat counter with 36;
  take, sendto fifo.in;
  take, sendto debug.in;



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