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ad_dds_1: Update for CORDIC algorithm integration
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Add parameters and the mechanism:
  - to select the sine generator (polynomial/CORDIC)
  - to select the CORDIC data width(default 16)
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AndreiGrozav committed Jul 18, 2018
1 parent 0e114a3 commit 4c32b47
Showing 1 changed file with 53 additions and 12 deletions.
65 changes: 53 additions & 12 deletions library/common/ad_dds_1.v
Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,12 @@

`timescale 1ns/100ps

module ad_dds_1 (
module ad_dds_1 #(

// parameters

parameter DDS_TYPE = 1,
parameter CORDIC_DW = 16) (

// interface

Expand All @@ -44,27 +49,63 @@ module ad_dds_1 (
input [15:0] scale,
output reg [15:0] dds_data);

// internal registers
// local parameters

localparam DDS_CORDIC_TYPE = 1;
localparam DDS_POLINOMIAL_TYPE = 2;

// internal signals

wire [15:0] sine_s;
wire [33:0] s1_data_s;
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

ad_dds_sine #(.DELAY_DATA_WIDTH(1)) i_dds_sine (
.clk (clk),
.angle (angle),
.sine (sine_s),
.ddata_in (1'b0),
.ddata_out ());
generate
if (DDS_TYPE == DDS_CORDIC_TYPE) begin

// the cordic module input angle width must be equal with it's width
wire [CORDIC_DW-1:0] angle_s;

if (CORDIC_DW >= 16) begin
assign angle_s = {angle,zeros[CORDIC_DW-16:0]};
assign sine16_s = sine_s[CORDIC_DW-1:CORDIC_DW-16];
end else begin
assign angle_s = angle[15:16-CORDIC_DW];
assign sine16_s = {sine_s,zeros[15-CORDIC_DW:0]};
end

ad_dds_sine_cordic #(
.CORDIC_DW(CORDIC_DW),
.DELAY_DW(1))
i_dds_sine (
.clk (clk),
.angle (angle_s),
.sine (sine_s),
.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
// scale for a 16 bit sine generator

ad_mul #(.DELAY_DATA_WIDTH(1)) i_dds_scale (
.clk (clk),
.data_a ({sine_s[15], sine_s}),
.data_a ({sine16_s[15], sine16_s}),
.data_b ({scale[15], scale}),
.data_p (s1_data_s),
.ddata_in (1'b0),
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