pluto_hdl_adi/library/common/ad_dds_1.v

130 lines
3.9 KiB
Verilog

// ***************************************************************************
// ***************************************************************************
// Copyright 2014 - 2017 (c) 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 ad_dds_1 #(
// parameters
parameter DDS_TYPE = 1,
parameter CORDIC_DW = 16,
parameter CORDIC_PHASE_DW = 16) (
// interface
input clk,
input [15:0] angle,
input [15:0] scale,
output reg [15:0] dds_data);
// local parameters
localparam DDS_CORDIC_TYPE = 1;
localparam DDS_POLINOMIAL_TYPE = 2;
// internal signals
wire [CORDIC_DW-1:0] sine_s;
wire [ 15:0] sine16_s;
wire [ 3:0] zeros;
wire [ 33:0] s1_data_s;
assign zeros = 0;
// sine
generate
if (DDS_TYPE == DDS_CORDIC_TYPE) begin
// the cordic module input angle width must be equal with it's width
wire [CORDIC_PHASE_DW:0] angle_s;
if (CORDIC_PHASE_DW >= 16) begin
assign angle_s = {angle,{CORDIC_PHASE_DW-15{1'b0}}};
end else begin
assign angle_s = {angle[15:16-CORDIC_PHASE_DW],1'b0};
end
if (CORDIC_DW >= 16) begin
assign sine16_s = sine_s[CORDIC_DW-1:CORDIC_DW-16];
end else begin
assign sine16_s = {sine_s,zeros[15-CORDIC_DW:0]};
end
ad_dds_sine_cordic #(
.CORDIC_DW(CORDIC_DW),
.PHASE_DW(CORDIC_PHASE_DW),
.DELAY_DW(1))
i_dds_sine (
.clk (clk),
.angle (angle_s[CORDIC_PHASE_DW:1]),
.sine (sine_s),
.cosine (),
.ddata_in (1'b0),
.ddata_out ());
end else begin
assign sine16_s = sine_s;
ad_dds_sine i_dds_sine (
.clk (clk),
.angle (angle),
.sine (sine_s),
.ddata_in (1'b0),
.ddata_out ());
end
endgenerate
// scale for a 16 bit sine generator
ad_mul #(.DELAY_DATA_WIDTH(1)) i_dds_scale (
.clk (clk),
.data_a ({sine16_s[15], sine16_s}),
.data_b ({scale[15], scale}),
.data_p (s1_data_s),
.ddata_in (1'b0),
.ddata_out ());
// dds data
always @(posedge clk) begin
dds_data <= s1_data_s[29:14];
end
endmodule
// ***************************************************************************
// ***************************************************************************