DDS Design Based on Vivado Calling ROM IP core

DDS Direct Digital Synthesizer

The following is the code of generating sine wave, triangle wave and square wave with MATLAB, which can be used directly.

 1 t=0:2*pi/2^12:2*pi
 2 y=0.5*sin(t)+0.5;
 3 r=ceil(y*(2^8-1)); %Convert decimal to integer. ceil It's up.
 4 fid = fopen('sin.coe','w'); %write to sin.coe File, used for initialization sin_rom
 5 fprintf(fid,'MEMORY_INITIALIZATION_RADIX=10;\n');
 6 fprintf(fid,'MEMORY_INITIALIZATION_VECTOR=\n');
 7 for i = 1:1:2^12
 8 fprintf(fid,'%d',r(i));
 9 if i==2^12
10 fprintf(fid,';');
11 else
12 fprintf(fid,',');
13 end
14 if i%15==0
15 fprintf(fid,'\n');
16 end
17 end
18 fclose(fid);
19 t=1:1:2^12;
20 y=(t<=2047);
21 r=ceil(y*(2^8-1));
22 fid = fopen('square.coe','w'); %write to square.coe，Used for initialization rom_square
23 fprintf(fid,'MEMORY_INITIALIZATION_RADIX=10;\n');
24 fprintf(fid,'MEMORY_INITIALIZATION_VECTOR=\n');
25 for i = 1:1:2^12
26 fprintf(fid,'%d',r(i));
27 if i==2^12
28 fprintf(fid,';');
29 else
30 fprintf(fid,',');
31 end
32 if i%15==0
33 fprintf(fid,'\n');
34 end
35 end
36 fclose(fid);
37 t=1:1:2^12;
38 y=[0.5:0.5/1024:1-0.5/1024, 1-0.5/1024:-0.5/1024:0, 0.5/1024:0.5/1024:0.5];
39 r=ceil(y*(2^8-1));
40 fid = fopen('triangular.coe','w'); %write to triangular.coe，Initialization of triangular waves rom
41 fprintf(fid,'MEMORY_INITIALIZATION_RADIX=10;\n');
42 fprintf(fid,'MEMORY_INITIALIZATION_VECTOR=\n');
43 for i = 1:1:2^12
44 fprintf(fid,'%d',r(i));
45 if i==2^12
46 fprintf(fid,';');
47 else
48 fprintf(fid,',');
49 end
50 if i%15==0
51 fprintf(fid,'\n');
52 end
53 end
54 fclose(fid);

The core of DDS design is to call IP ROM. Viado calls ROM in a way similar to ISE. It loads. coe files. I take notes here to prevent forgetting.

This is the principle diagram of DDS. DDS is not as abstruse as its name says. Its core is to control the frequency of fword input and phase word pword input. Finally, it can call IP verification to find tables. The code is very simple. Here is DDS design code.

 1 module DDS(
 2             input mclk,
 3             input rst_n,
 4             input [31:0]fword,//frequency control
 5             input [11:0]pword,//phase control
 6             
 7             output [9:0]da_data
 8     );
 9     
10     reg [31:0]r_fword;
11     reg [11:0]r_pword;
12     reg [31:0]fcnt;
13     
14     wire [11:0]addr_rom;
15     
16     //Synchronization Register
17     always @(posedge mclk)
18     begin
19             r_fword <= fword;
20             r_pword <= pword;
21         end
22       
23     always @(posedge mclk or negedge rst_n)
24     begin
25         if(!rst_n)
26             fcnt <= 32'd0;
27         else
28             fcnt <= fcnt + r_fword;
29         end
30     
31     assign addr_rom = fcnt[31:20] + r_pword;
32     
33     //custom sin_rom
34     sin_rom sin_rom (
35     .clka(mclk),    // input wire clka
36     .addra(addr_rom),  // input wire [11 : 0] addra
37     .douta(da_data)  // output wire [9 : 0] douta
38     );
39 
40 endmodule

DDS_design

Using vivado to call the IP Core ROM tutorial is as follows

Click IP catalog

Select block memory, then double-click

Check the show disabled ports option

Enter the ROM name, and I'm going to reconfigure a square-wave ROM for demonstration. It's called square_rom.

Select single ports ROM here

Selecting the parameters as shown in the figure above, port width is the data width, and we set it to 10 bits according to the code requirements.

Portwidth is the depth of data, that is, how many such data, I opened the generated square.coe file can clearly see a total of 4096 such data.

The always enable is that ROM is always in working state and no enabling signal is needed.

Here is to load the. coe file, check load init file, then click browse to load the square.coe file just generated into ROM, and finally click OK.

Select generate to generate IP core

Open the file as shown.

Instantiate the generated IP core

Finally, test files are written for testing.

Finally, right-click da_data to select wave style to select analog, you will see the analog waveform, but sometimes you need to set up the display of the analog waveform. Similarly, right-click da_data to select wave style to select analog set, and select the parameters as shown in the following figure.

Finally, the square wave waveform can be obtained.

You can also make the other two waveforms according to this method.

Reprinted please indicate the source: Tough Enough (Ninghe River)

Original address: http://www.cnblogs.com/ninghechuan/p/6421360.html

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DDS Design Based on Vivado Calling ROM IP core

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