ship: DRAM

== Ports ===========================================================
data  in:    inAddrRead
data  in:    inAddrWrite
data  in:    inDataWrite

data  out:   out

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

== Fleeterpreter ====================================================
    public void service() { }
== FleetSim ==============================================================

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

  // FIXME: use the other chip (64-bit data bus)

  reg         dram_addr_r;
  reg         dram_isread;
  reg         dram_write_data_push;
  reg         dram_read_data_pop;
  reg  [`DATAWIDTH-1:0]  out_d;

  assign dram_addr_r_ = dram_addr_r;
  assign dram_isread_ = dram_isread;
  assign dram_addr_ = !dram_isread ? inAddrWrite_d[31:0] : inAddrRead_d[31:0];
  assign dram_write_data_push_ = dram_write_data_push;
  assign dram_read_data_pop_ = dram_read_data_pop;
  assign dram_write_data_ = inDataWrite_d[31:0];
  assign out_d_ = out_d;

  always @(posedge clk) begin

    if (!rst) begin
      `reset
      dram_isread <= 0;
      dram_addr_r <= 0;
      dram_read_data_pop <= 0;

    end else begin

      if (!inAddrRead_r  && inAddrRead_a)  inAddrRead_a  <= 0;
      if (!inDataWrite_r && inDataWrite_a) inDataWrite_a <= 0;
      if (!inAddrWrite_r && inAddrWrite_a) inAddrWrite_a <= 0;
      if ( out_r         && out_a)         out_r <= 0;

      if (dram_addr_r && !dram_addr_a) begin
         // busy
      end else if (dram_addr_r &&  dram_addr_a && !dram_isread) begin
          dram_addr_r <= 0;
          inAddrWrite_a <= 1;
          inDataWrite_a <= 1;
      end else if (dram_addr_r &&  dram_addr_a && dram_isread) begin
          dram_addr_r <= 0;
          inAddrRead_a <= 1;
          out_d <= dram_read_data;
          out_r <= 1;
      end else if (inAddrWrite_r && !inAddrWrite_a && inDataWrite_r && !inDataWrite_a && !dram_addr_r && !dram_addr_a) begin
          dram_addr_r <= 1;
          dram_isread <= 0;
      end else if (inAddrRead_r && !inAddrRead_a && !out_r && !out_a && !dram_addr_r && !dram_addr_a) begin
          dram_addr_r <= 1;
          dram_isread <= 1;
      end
    end
  end


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

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