// *************************************************************************** // *************************************************************************** // Copyright (C) 2014-2023 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: // // // 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. // // *************************************************************************** // *************************************************************************** // this is a sine function (approximate), the basic idea is to approximate sine as a // polynomial function (there are a lot of stuff about this on the web) `timescale 1ns/100ps module ad_dds_sine #( parameter DELAY_DATA_WIDTH = 16 ) ( // sine = sin(angle) input clk, input [15:0] angle, output [15:0] sine, input [(DELAY_DATA_WIDTH-1):0] ddata_in, output [(DELAY_DATA_WIDTH-1):0] ddata_out ); // internal registers reg [33:0] s1_data_p = 'd0; reg [33:0] s1_data_n = 'd0; reg [15:0] s1_angle = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s1_ddata = 'd0; reg [18:0] s2_data_0 = 'd0; reg [18:0] s2_data_1 = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s2_ddata = 'd0; reg [18:0] s3_data = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s3_ddata = 'd0; reg [33:0] s4_data2_p = 'd0; reg [33:0] s4_data2_n = 'd0; reg [16:0] s4_data1_p = 'd0; reg [16:0] s4_data1_n = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s4_ddata = 'd0; reg [16:0] s5_data2_0 = 'd0; reg [16:0] s5_data2_1 = 'd0; reg [16:0] s5_data1 = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s5_ddata = 'd0; reg [16:0] s6_data2 = 'd0; reg [16:0] s6_data1 = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s6_ddata = 'd0; reg [33:0] s7_data = 'd0; reg [(DELAY_DATA_WIDTH-1):0] s7_ddata = 'd0; reg [15:0] sine_int = 'd0; reg [(DELAY_DATA_WIDTH-1):0] ddata_out_int = 'd0; // internal signals wire [15:0] angle_s; wire [33:0] s1_data_s; wire [(DELAY_DATA_WIDTH-1):0] s1_ddata_s; wire [15:0] s1_angle_s; wire [33:0] s4_data2_s; wire [(DELAY_DATA_WIDTH-1):0] s4_ddata_s; wire [16:0] s4_data1_s; wire [33:0] s7_data2_s; wire [33:0] s7_data1_s; wire [(DELAY_DATA_WIDTH-1):0] s7_ddata_s; // make angle 2's complement assign angle_s = {~angle[15], angle[14:0]}; // level 1 - intermediate ad_mul #( .DELAY_DATA_WIDTH(DELAY_DATA_WIDTH+16) ) i_mul_s1 ( .clk (clk), .data_a ({angle_s[15], angle_s}), .data_b ({angle_s[15], angle_s}), .data_p (s1_data_s), .ddata_in ({ddata_in, angle_s}), .ddata_out ({s1_ddata_s, s1_angle_s})); // 2's complement versions always @(posedge clk) begin s1_data_p <= s1_data_s; s1_data_n <= ~s1_data_s + 1'b1; s1_angle <= s1_angle_s; s1_ddata <= s1_ddata_s; end // select partial products always @(posedge clk) begin s2_data_0 <= (s1_angle[15] == 1'b0) ? s1_data_n[31:13] : s1_data_p[31:13]; s2_data_1 <= {s1_angle[15], s1_angle[15:0], 2'b00}; s2_ddata <= s1_ddata; end // unit-sine always @(posedge clk) begin s3_data <= s2_data_0 + s2_data_1; s3_ddata <= s2_ddata; end // level 2 - final ad_mul #( .DELAY_DATA_WIDTH(DELAY_DATA_WIDTH+17) ) i_mul_s2 ( .clk (clk), .data_a (s3_data[16:0]), .data_b (s3_data[16:0]), .data_p (s4_data2_s), .ddata_in ({s3_ddata, s3_data[16:0]}), .ddata_out ({s4_ddata_s, s4_data1_s})); // 2's complement versions always @(posedge clk) begin s4_data2_p <= s4_data2_s; s4_data2_n <= ~s4_data2_s + 1'b1; s4_data1_p <= s4_data1_s; s4_data1_n <= ~s4_data1_s + 1'b1; s4_ddata <= s4_ddata_s; end // select partial products always @(posedge clk) begin s5_data2_0 <= (s4_data1_p[16] == 1'b1) ? s4_data2_n[31:15] : s4_data2_p[31:15]; s5_data2_1 <= s4_data1_n; s5_data1 <= s4_data1_p; s5_ddata <= s4_ddata; end // corrected-sine always @(posedge clk) begin s6_data2 <= s5_data2_0 + s5_data2_1; s6_data1 <= s5_data1; s6_ddata <= s5_ddata; end // full-scale ad_mul #( .DELAY_DATA_WIDTH(1) ) i_mul_s3_2 ( .clk (clk), .data_a (s6_data2), .data_b (17'h1d08), .data_p (s7_data2_s), .ddata_in (1'b0), .ddata_out ()); ad_mul #( .DELAY_DATA_WIDTH(DELAY_DATA_WIDTH) ) i_mul_s3_1 ( .clk (clk), .data_a (s6_data1), .data_b (17'h7fff), .data_p (s7_data1_s), .ddata_in (s6_ddata), .ddata_out (s7_ddata_s)); // corrected sum always @(posedge clk) begin s7_data <= s7_data2_s + s7_data1_s; s7_ddata <= s7_ddata_s; end // output registers assign sine = sine_int; assign ddata_out = ddata_out_int; always @(posedge clk) begin sine_int <= s7_data[30:15]; ddata_out_int <= s7_ddata; end endmodule