//
// Copyright 2011 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//


module fifo_to_gpmc_async
  (input clk, input reset, input clear,
   input [17:0] data_i, input src_rdy_i, output dst_rdy_o,
   output [15:0] EM_D, input EM_NCS, input EM_NOE,
   input [15:0] frame_len);

   // Synchronize the async control signals
   reg [2:0] 	cs_del, oe_del;
   reg [15:0] 	counter;
   
   always @(posedge clk)
     if(reset)
       begin
	  cs_del <= 3'b11;
	  oe_del <= 3'b11;
       end
     else
       begin
	  cs_del <= { cs_del[1:0], EM_NCS };
	  oe_del <= { oe_del[1:0], EM_NOE };
       end

   wire do_read = ( (~cs_del[1] | ~cs_del[2]) & (oe_del[1:0] == 2'b01));  // change output on trailing edge
   wire first_read = (counter == 0);
   wire last_read = ((counter+1) == frame_len);

   assign EM_D = data_i[15:0];

   assign dst_rdy_o = do_read;

endmodule // fifo_to_gpmc_async