Subversion Repositories s1_core

/*

 * S1 Testbench

 *

 * (C) 2007 Fabrizio Fazzino

 *

 * LICENSE:

 * This is a Free Hardware Design; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * version 2 as published by the Free Software Foundation.

 * The above named 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.

 *

 * DESCRIPTION:

 * This is the testbench for the functional verification of the

 * S1 Core: it makes and instance of the S1 module to make it

 * possible to access one or more memory harnesses.

 */

`include "s1_defs.h"

module testbench ();

  /*

   * Wires

   */

  // Interrupt Requests

  wire[63:0] sys_irq;

  // Wishbone Master inputs / Wishbone Slave ouputs

  wire wb_ack;                                 // Ack

  wire[(`WB_DATA_WIDTH-1):0] wb_datain;        // Data In

  // Wishbone Master outputs / Wishbone Slave inputs

  wire wb_cycle;                               // Cycle Start

  wire wb_strobe;                              // Strobe Request

  wire wb_we;                                  // Write Enable

  wire[`WB_ADDR_WIDTH-1:0] wb_addr;            // Address Bus

  wire[`WB_DATA_WIDTH-1:0] wb_dataout;         // Data Out

  wire[`WB_DATA_WIDTH/8-1:0] wb_sel;           // Select Output

  // Separate Cycle, Strobe and Ack wires for ROM and RAM memory harnesses

  wire wb_cycle_ram;

  wire wb_cycle_rom;

  wire wb_strobe_ram;

  wire wb_strobe_rom;

  wire wb_ack_ram;

  wire wb_ack_rom;

  // Decode the address and select the proper memory bank

  assign wb_cycle_rom  = ( (wb_addr[39:12]==28'hFFF0000) ? wb_cycle : 0 );

  assign wb_strobe_rom = ( (wb_addr[39:12]==28'hFFF0000) ? wb_strobe : 0 );

  assign wb_cycle_ram  = ( (wb_addr[39:16]==24'h000004) ? wb_cycle : 0 );

  assign wb_strobe_ram = ( (wb_addr[39:16]==24'h000004) ? wb_strobe : 0 );

  assign wb_ack = wb_ack_ram | wb_ack_rom;

  /*

   * Registers

   */

  // System signals

  reg sys_clock;

  reg sys_reset;

  /*

   * Behavior

   */

  always #1 sys_clock = ~sys_clock;

  assign sys_irq = 64'b0;

  initial begin

    // Display start message

    $display("INFO: TBENCH: Starting S1 Core simulation...");

    // Create VCD trace file

    $dumpfile("trace.vcd");

    $dumpvars();

    // Run the simulation

    sys_clock <= 1'b1;

    sys_reset <= 1'b1;

    #1000

    sys_reset <= 1'b0;

    #49000

    $display("INFO: TBENCH: Completed S1 Core simulation!");

    $finish;

  end

  /*

   * Module instances

   */

  // S1 Core

  s1_top s1_top_0 (

    // System inputs

    .sys_clock_i(sys_clock),

    .sys_reset_i(sys_reset),

    .sys_irq_i(sys_irq),

    // Wishbone Master inputs

    .wbm_ack_i(wb_ack),

    .wbm_data_i(wb_datain),

    // Wishbone Master outputs

    .wbm_cycle_o(wb_cycle),

    .wbm_strobe_o(wb_strobe),

    .wbm_we_o(wb_we),

    .wbm_addr_o(wb_addr),

    .wbm_data_o(wb_dataout),

    .wbm_sel_o(wb_sel)

  );

  // Wishbone memory harness used as ROM

  mem_harness rom_harness (

    // System inputs

    .sys_clock_i(sys_clock),

    .sys_reset_i(sys_reset),

    // Wishbone Slave inputs

    .wbs_addr_i(wb_addr),

    .wbs_data_i(wb_dataout),

    .wbs_cycle_i(wb_cycle_rom),

    .wbs_strobe_i(wb_strobe_rom),

    .wbs_sel_i(wb_sel),

    .wbs_we_i(wb_we),

    // Wishbone Slave outputs

    .wbs_data_o(wb_datain),

    .wbs_ack_o(wb_ack_rom)

  );

  // Wishbone memory harness used as RAM

  mem_harness ram_harness (

    // System inputs

    .sys_clock_i(sys_clock),

    .sys_reset_i(sys_reset),

    // Wishbone Slave inputs

    .wbs_addr_i(wb_addr),

    .wbs_data_i(wb_dataout),

    .wbs_cycle_i(wb_cycle_ram),

    .wbs_strobe_i(wb_strobe_ram),

    .wbs_sel_i(wb_sel),

    .wbs_we_i(wb_we),

    // Wishbone Slave outputs

    .wbs_data_o(wb_datain),

    .wbs_ack_o(wb_ack_ram)

  );

  /*

   * Parameters for memory harnesses

   */

  // ROM has Physical Address range [0xFFF0000000:0xFFF0000FFF]

  // so size is 4 KByte and requires 12 address bits

  // 3 of which are ignored being a 64-bit memory => addr_bits=9

  // (it was section RED_SEC in the official OpenSPARC-T1 testbench)

  defparam rom_harness.addr_bits = 9;

  defparam rom_harness.memfilename = "rom_harness.hex";

  defparam rom_harness.memdefaultcontent = 64'h0100000001000000;

  // RAM has Physical Address range [0x0000040000:0x000004FFFF]

  // so size is 64 KByte and requires 16 address bits

  // 3 of which are ignored being a 64-bit memory => addr_bits=13

  // (it was section RED_EXT_SEC in the official OpenSPARC-T1 testbench)

  defparam ram_harness.addr_bits = 13;

  defparam ram_harness.memfilename = "ram_harness.hex";

  defparam ram_harness.memdefaultcontent = 64'h0100000001000000;

endmodule