pluto_hdl_adi/library/axi_mc_controller/delay.v

// ***************************************************************************
// ***************************************************************************
// Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
//
// Each core or library found in this collection may have its own licensing terms. 
// The user should keep this in in mind while exploring these cores. 
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//   1. The GNU General Public License version 2 as published by the
//      Free Software Foundation, which can be found in the top level directory, or at:
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// https://github.com/analogdevicesinc/hdl/blob/dev/LICENSE
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`timescale 1ns / 1ps

module delay
//----------- Parameters Declarations -------------------------------------------
#(
    parameter DELAY = 128
)
//----------- Ports Declarations -----------------------------------------------
(
    input       clk_i,
    input       rst_n_i,
    input       sig_i,
    output reg  sig_o
);
//------------------------------------------------------------------------------
//----------- Registers Declarations -------------------------------------------
//------------------------------------------------------------------------------
reg [DELAY-1:0] shift_reg;

//------------------------------------------------------------------------------
//----------- Assign/Always Blocks ---------------------------------------------
//------------------------------------------------------------------------------
always @(posedge clk_i)
begin
    if(rst_n_i == 0)
    begin
        shift_reg   <= 0;
        sig_o       <= 0;
    end
    else
    begin
        shift_reg   <= {shift_reg[DELAY-2:0], sig_i};
        sig_o       <= shift_reg[DELAY-1];
    end
end

endmodule