Subversion Repositories wf3d

//=======================================================================

// Project Monophony

//   Wire-Frame 3D Graphics Accelerator IP Core

//

// File:

//   fm_cinterface.v

//

// Abstract:

//   Memory Interconnect command interface

//

// Author:

//   Kenji Ishimaru (info.info.wf3d@gmail.com)

//

//======================================================================

//

// Copyright (c) 2016, Kenji Ishimaru

// All rights reserved.

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//

//  -Redistributions of source code must retain the above copyright notice,

//   this list of conditions and the following disclaimer.

//  -Redistributions in binary form must reproduce the above copyright notice,

//   this list of conditions and the following disclaimer in the documentation

//   and/or other materials provided with the distribution.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR

// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;

// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

//

// Revision History

module fm_cinterface (

  clk_core,

  rst_x,

  // bus side port

  i_bstr,

  i_bdata,

  o_back,

  // internal port

  o_istr,

  o_idata,

  i_iack

);

parameter P_WIDTH = 8;

////////////////////////////

// I/O definitions

////////////////////////////

input         i_bstr;         // input strobe

input  [P_WIDTH-1:0]

              i_bdata;        // input data

output        o_back;         // output acknowledge

output        o_istr;         // output strobe

output [P_WIDTH-1:0]

              o_idata;        // output data

input         i_iack;         // input acknowledge

input         clk_core;            // system clock

input         rst_x;          // system reset

/////////////////////////

//  register definition

/////////////////////////

// input register

reg           r_bstr;

reg    [P_WIDTH-1:0]

              r_bdata;

reg           r_back;

/////////////////////////

//  wire definition

/////////////////////////

wire          w_empty;

/////////////////////////

//  assign statement

/////////////////////////

assign o_istr = !w_empty;

assign o_back = r_back;

/////////////////////////

//  always statement

/////////////////////////

always @(posedge clk_core or negedge rst_x) begin

  if (~rst_x) begin

    r_bstr <= 1'b0;

  end else begin

    r_bstr <= i_bstr;

  end

end

always @(posedge clk_core or negedge rst_x) begin

  if (~rst_x) begin

    r_back <= 1'b0;

  end else begin

    r_back <= i_iack;

  end

end

always @(posedge clk_core) begin

  r_bdata <= i_bdata;

end

/////////////////////////

//  module instanciation

/////////////////////////

// input data fifo

fm_ififo #(P_WIDTH) fifo (

  .i_wstrobe(r_bstr),

  .i_dt(r_bdata),

  .o_full(),

  .i_renable(i_iack),

  .o_dt(o_idata),

  .o_empty(w_empty),

  .clk_core(clk_core),

  .rst_x(rst_x)

);

endmodule