hobbskw
Junior Member level 3
Hello,
I have written code to generate a simple triangle wave that varies from -1250 to 1250 (-MAX to +MAX). I used MATLAB to verify that the logic itself works for generating a triangle wave, by copy/pasting the code into MATLAB and making minor syntax changes so it would work in that environment. However, when I simulate it in Vivado, the counter variable only alternates between 1 and 0 and does not count up to MAX or down to -MAX. I suspect there is something wrong with how the code is written in Verilog. Would anyone be able to shed light on this problem? I would greatly appreciate any help!
Code:
Testbench code:
Simulation result:
MATLAB code:
MATLAB result:
I have written code to generate a simple triangle wave that varies from -1250 to 1250 (-MAX to +MAX). I used MATLAB to verify that the logic itself works for generating a triangle wave, by copy/pasting the code into MATLAB and making minor syntax changes so it would work in that environment. However, when I simulate it in Vivado, the counter variable only alternates between 1 and 0 and does not count up to MAX or down to -MAX. I suspect there is something wrong with how the code is written in Verilog. Would anyone be able to shed light on this problem? I would greatly appreciate any help!
Code:
Code:
`timescale 1ns / 1ps
module sine_LUT(
input clk,
output led
);
reg[12:0] counter = 0;
integer updown = 1;
localparam MAX = 1250;
always@(posedge clk) begin
if (counter > MAX)
begin
counter <= MAX;
updown <= updown * -1;
end
if (counter < MAX*(-1))
begin
counter <= MAX*(-1);
updown <= updown * -1;
end
counter <= counter + updown;
end
assign led = (counter < 20)?1:0;
endmoduleTestbench code:
Code:
`timescale 1ns / 1ps
module testbenchh;
reg clk = 0;
wire led;
sine_LUT UUT (clk, led);
always #5 clk = ~clk;
endmoduleSimulation result:
MATLAB code:
Code:
clc
clear
counter = 0;
updown = 1;
MAX = 1250;
T = 10000;
val = zeros(T);
time = zeros(T);
for t = 1:T
if (counter > MAX)
counter = MAX;
updown = updown * -1;
end
if (counter < MAX*(-1))
counter = MAX*(-1);
updown = updown * -1;
end
counter = counter + updown;
val(t) = counter;
time(t) = t;
end
plot(time, val);
xlim([0 T]);MATLAB result: