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[/] [a-z80/] [trunk/] [host/] [basic_nexys3/] [ipcore_dir/] [clock/] [example_design/] [clock_exdes.v] - Rev 8
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// file: clock_exdes.v // // (c) Copyright 2008 - 2011 Xilinx, Inc. All rights reserved. // // This file contains confidential and proprietary information // of Xilinx, Inc. and is protected under U.S. and // international copyright and other intellectual property // laws. // // DISCLAIMER // This disclaimer is not a license and does not grant any // rights to the materials distributed herewith. Except as // otherwise provided in a valid license issued to you by // Xilinx, and to the maximum extent permitted by applicable // law: (1) THESE MATERIALS ARE MADE AVAILABLE "AS IS" AND // WITH ALL FAULTS, AND XILINX HEREBY DISCLAIMS ALL WARRANTIES // AND CONDITIONS, EXPRESS, IMPLIED, OR STATUTORY, INCLUDING // BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, NON- // INFRINGEMENT, OR FITNESS FOR ANY PARTICULAR PURPOSE; and // (2) Xilinx shall not be liable (whether in contract or tort, // including negligence, or under any other theory of // liability) for any loss or damage of any kind or nature // related to, arising under or in connection with these // materials, including for any direct, or any indirect, // special, incidental, or consequential loss or damage // (including loss of data, profits, goodwill, or any type of // loss or damage suffered as a result of any action brought // by a third party) even if such damage or loss was // reasonably foreseeable or Xilinx had been advised of the // possibility of the same. // // CRITICAL APPLICATIONS // Xilinx products are not designed or intended to be fail- // safe, or for use in any application requiring fail-safe // performance, such as life-support or safety devices or // systems, Class III medical devices, nuclear facilities, // applications related to the deployment of airbags, or any // other applications that could lead to death, personal // injury, or severe property or environmental damage // (individually and collectively, "Critical // Applications"). Customer assumes the sole risk and // liability of any use of Xilinx products in Critical // Applications, subject only to applicable laws and // regulations governing limitations on product liability. // // THIS COPYRIGHT NOTICE AND DISCLAIMER MUST BE RETAINED AS // PART OF THIS FILE AT ALL TIMES. // //---------------------------------------------------------------------------- // Clocking wizard example design //---------------------------------------------------------------------------- // This example design instantiates the created clocking network, where each // output clock drives a counter. The high bit of each counter is ported. //---------------------------------------------------------------------------- `timescale 1ps/1ps module clock_exdes #( parameter TCQ = 100 ) (// Clock in ports input CLK_IN1, // Reset that only drives logic in example design input COUNTER_RESET, output [2:1] CLK_OUT, // High bits of counters driven by clocks output [2:1] COUNT, // Status and control signals output LOCKED ); // Parameters for the counters //------------------------------- // Counter width localparam C_W = 16; localparam NUM_C = 2; genvar count_gen; // When the clock goes out of lock, reset the counters wire reset_int = !LOCKED || COUNTER_RESET; reg [NUM_C:1] rst_sync; reg [NUM_C:1] rst_sync_int; reg [NUM_C:1] rst_sync_int1; reg [NUM_C:1] rst_sync_int2; // Declare the clocks and counters wire [NUM_C:1] clk_int; wire [NUM_C:1] clk_n; wire [NUM_C:1] clk; reg [C_W-1:0] counter [NUM_C:1]; // Instantiation of the clocking network //-------------------------------------- clock clknetwork (// Clock in ports .CLK_IN1 (CLK_IN1), // Clock out ports .CLK_OUT1 (clk_int[1]), .CLK_OUT2 (clk_int[2]), // Status and control signals .LOCKED (LOCKED)); genvar clk_out_pins; generate for (clk_out_pins = 1; clk_out_pins <= NUM_C; clk_out_pins = clk_out_pins + 1) begin: gen_outclk_oddr assign clk_n[clk_out_pins] = ~clk[clk_out_pins]; ODDR2 clkout_oddr (.Q (CLK_OUT[clk_out_pins]), .C0 (clk[clk_out_pins]), .C1 (clk_n[clk_out_pins]), .CE (1'b1), .D0 (1'b1), .D1 (1'b0), .R (1'b0), .S (1'b0)); end endgenerate // Connect the output clocks to the design //----------------------------------------- assign clk[1] = clk_int[1]; assign clk[2] = clk_int[2]; // Reset synchronizer //----------------------------------- generate for (count_gen = 1; count_gen <= NUM_C; count_gen = count_gen + 1) begin: counters_1 always @(posedge reset_int or posedge clk[count_gen]) begin if (reset_int) begin rst_sync[count_gen] <= 1'b1; rst_sync_int[count_gen]<= 1'b1; rst_sync_int1[count_gen]<= 1'b1; rst_sync_int2[count_gen]<= 1'b1; end else begin rst_sync[count_gen] <= 1'b0; rst_sync_int[count_gen] <= rst_sync[count_gen]; rst_sync_int1[count_gen] <= rst_sync_int[count_gen]; rst_sync_int2[count_gen] <= rst_sync_int1[count_gen]; end end end endgenerate // Output clock sampling //----------------------------------- generate for (count_gen = 1; count_gen <= NUM_C; count_gen = count_gen + 1) begin: counters always @(posedge clk[count_gen] or posedge rst_sync_int2[count_gen]) begin if (rst_sync_int2[count_gen]) begin counter[count_gen] <= #TCQ { C_W { 1'b 0 } }; end else begin counter[count_gen] <= #TCQ counter[count_gen] + 1'b 1; end end // alias the high bit of each counter to the corresponding // bit in the output bus assign COUNT[count_gen] = counter[count_gen][C_W-1]; end endgenerate endmodule