// ***************************************************************************
// ***************************************************************************
// Copyright (C) 2022-2023 Analog Devices, Inc. All rights reserved.
//
// In this HDL repository, there are many different and unique modules, consisting
// of various HDL (Verilog or VHDL) components. The individual modules are
// developed independently, and may be accompanied by separate and unique license
// terms.
//
// The user should read each of these license terms, and understand the
// freedoms and responsibilities that he or she has by using this source/core.
//
// This core 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.
//
// Redistribution and use of source or resulting binaries, with or without modification
// of this file, are permitted under one of the following two license terms:
//
//   1. The GNU General Public License version 2 as published by the
//      Free Software Foundation, which can be found in the top level directory
//      of this repository (LICENSE_GPL2), and also online at:
//      <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
//
// OR
//
//   2. An ADI specific BSD license, which can be found in the top level directory
//      of this repository (LICENSE_ADIBSD), and also on-line at:
//      https://github.com/analogdevicesinc/hdl/blob/master/LICENSE_ADIBSD
//      This will allow to generate bit files and not release the source code,
//      as long as it attaches to an ADI device.
//
// ***************************************************************************
// ***************************************************************************

`timescale 1ns/100ps

module system_top (

  // clock and resets
  input           sys_clk,
  input           sys_resetn,

  // ddr3
  output          ddr3_clk_p,
  output          ddr3_clk_n,
  output  [14:0]  ddr3_a,
  output  [ 2:0]  ddr3_ba,
  output          ddr3_cke,
  output          ddr3_cs_n,
  output          ddr3_odt,
  output          ddr3_reset_n,
  output          ddr3_we_n,
  output          ddr3_ras_n,
  output          ddr3_cas_n,
  inout   [ 7:0]  ddr3_dqs_p,
  inout   [ 7:0]  ddr3_dqs_n,
  inout   [63:0]  ddr3_dq,
  output  [ 7:0]  ddr3_dm,
  input           ddr3_rzq,
  input           ddr3_ref_clk,

  // ethernet
  input           eth_ref_clk,
  input           eth_rxd,
  output          eth_txd,
  output          eth_mdc,
  inout           eth_mdio,
  output          eth_resetn,
  input           eth_intn,

  // board gpio
  input   [10:0]  gpio_bd_i,
  output  [15:0]  gpio_bd_o,

  // flash
  output          flash_oen,
  output  [ 1:0]  flash_cen,
  output  [27:0]  flash_addr,
  inout   [31:0]  flash_data,
  output          flash_wen,
  output          flash_advn,
  output          flash_clk,
  output          flash_resetn
);

  // internal signals
  wire            eth_reset;
  wire            eth_mdio_i;
  wire            eth_mdio_o;
  wire            eth_mdio_t;
  wire    [63:0]  gpio_i;
  wire    [63:0]  gpio_o;
  wire    [23:0]  flash_addr_raw;

  // assignments

  // board stuff
  assign eth_resetn = ~eth_reset;
  assign eth_mdio_i = eth_mdio;
  assign eth_mdio = (eth_mdio_t == 1'b1) ? 1'bz : eth_mdio_o;

  assign ddr3_a[14:12] = 3'd0;

  assign gpio_i[63:32] = gpio_o[63:32];
  assign gpio_i[31:27] = gpio_o[31:27];
  assign gpio_i[26:16] = gpio_bd_i;
  assign gpio_i[15: 0] = gpio_o[15: 0];

  assign gpio_bd_o = gpio_o[15:0];

  // User code space at offset 0x0930_0000 per Intel's Board Update Portal
  // reference design used to program flash
  assign flash_addr = flash_addr_raw + 28'h9300000;

  // Common Flash interface assignments
  assign  flash_resetn = 1'b1;
  assign  flash_advn   = 1'b0;
  assign  flash_clk    = 1'b0;
  assign  flash_cen[1] = flash_cen[0];

  // instantiations
  system_bd i_system_bd (
    .sys_clk_clk (sys_clk),

    .sys_ddr3_cntrl_mem_mem_ck (ddr3_clk_p),
    .sys_ddr3_cntrl_mem_mem_ck_n (ddr3_clk_n),
    .sys_ddr3_cntrl_mem_mem_a (ddr3_a[11:0]),
    .sys_ddr3_cntrl_mem_mem_ba (ddr3_ba),
    .sys_ddr3_cntrl_mem_mem_cke (ddr3_cke),
    .sys_ddr3_cntrl_mem_mem_cs_n (ddr3_cs_n),
    .sys_ddr3_cntrl_mem_mem_odt (ddr3_odt),
    .sys_ddr3_cntrl_mem_mem_reset_n (ddr3_reset_n),
    .sys_ddr3_cntrl_mem_mem_we_n (ddr3_we_n),
    .sys_ddr3_cntrl_mem_mem_ras_n (ddr3_ras_n),
    .sys_ddr3_cntrl_mem_mem_cas_n (ddr3_cas_n),
    .sys_ddr3_cntrl_mem_mem_dqs (ddr3_dqs_p[7:0]),
    .sys_ddr3_cntrl_mem_mem_dqs_n (ddr3_dqs_n[7:0]),
    .sys_ddr3_cntrl_mem_mem_dq (ddr3_dq[63:0]),
    .sys_ddr3_cntrl_mem_mem_dm (ddr3_dm[7:0]),
    .sys_ddr3_cntrl_oct_oct_rzqin (ddr3_rzq),
    .sys_ddr3_cntrl_pll_ref_clk_clk (ddr3_ref_clk),

    .sys_ethernet_mdio_mdc (eth_mdc),
    .sys_ethernet_mdio_mdio_in (eth_mdio_i),
    .sys_ethernet_mdio_mdio_out (eth_mdio_o),
    .sys_ethernet_mdio_mdio_oen (eth_mdio_t),
    .sys_ethernet_ref_clk_clk (eth_ref_clk),
    .sys_ethernet_reset_reset (eth_reset),
    .sys_ethernet_sgmii_rxp_0 (eth_rxd),
    .sys_ethernet_sgmii_txp_0 (eth_txd),

    .sys_gpio_bd_in_port (gpio_i[31:0]),
    .sys_gpio_bd_out_port (gpio_o[31:0]),
    .sys_gpio_in_export (gpio_i[63:32]),
    .sys_gpio_out_export (gpio_o[63:32]),

    .pr_rom_data_nc_rom_data('h0),

    .sys_rst_reset_n (sys_resetn),

    .sys_flash_tcm_address_out (flash_addr_raw),
    .sys_flash_tcm_read_n_out (flash_oen),
    .sys_flash_tcm_write_n_out (flash_wen),
    .sys_flash_tcm_data_out (flash_data),
    .sys_flash_tcm_chipselect_n_out (flash_cen[0]));

endmodule