Hi, I'm not quite sure if this vhdl code and testbench is correct for the given task. Can you take a look?
Design a one-hour kitchen timer. The device should have buttons/switches to start and stop the timer, as well as to set the desired time interval for the alarm. Realize the task using the software package Quartus or in GHDL, confirm the correctness of the project task by simulation.
This is VHDL code:
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Kitchen_Timer is
port (
clk : in std_logic; -- Clock input
reset : in std_logic; -- Reset input
start : in std_logic; -- Start button input
stop : in std_logic; -- Stop button input
alarm : out std_logic -- Alarm output
);
end entity Kitchen_Timer;
-- Declare the architecture for the kitchen timer
architecture Behavioral of Kitchen_Timer is
signal count : integer range 0 to 3600 := 0; -- Counter for timer
signal alarming : std_logic := '0'; -- Signal to indicate alarming interval
signal alarm_en : std_logic := '0'; -- Signal to enable alarming interval
signal alarm_cnt : integer range 0 to 600 := 0; -- Counter for alarming interval
begin
-- Process to control the kitchen timer and alarming interval
process (clk, reset)
begin
if (reset = '1') then
count <= 0;
alarming <= '0';
alarm_en <= '0';
alarm_cnt <= 0;
elsif (rising_edge(clk)) then
if (stop = '1') then
count <= 0;
alarming <= '0';
alarm_en <= '0';
alarm_cnt <= 0;
elsif (start = '1' and count < 3600) then
count <= count + 1;
if (count = 3600) then
count <= 0;
alarming <= '0';
alarm_en <= '0';
alarm_cnt <= 0;
elsif (count > 0) then
alarm_en <= '1';
end if;
end if;
if (alarm_en = '1') then
if (alarm_cnt < 600) then
alarm_cnt <= alarm_cnt + 1;
else
alarm_cnt <= 0;
alarming <= '1';
end if;
end if;
end if;
end process;
-- Assign the alarm output
alarm <= alarming;
end architecture Behavioral; ```
This is Testbench:
```library ieee;
use ieee.std_logic_1164.all;
entity tb_Kitchen_Timer is
end tb_Kitchen_Timer;
architecture tb of tb_Kitchen_Timer is
component Kitchen_Timer
port (clk : in std_logic;
reset : in std_logic;
start : in std_logic;
stop : in std_logic;
alarm : out std_logic);
end component;
signal clk : std_logic;
signal reset : std_logic;
signal start : std_logic;
signal stop : std_logic;
signal alarm : std_logic;
constant TbPeriod : time := 1000 ns; -- EDIT Put right period here
signal TbClock : std_logic := '0';
signal TbSimEnded : std_logic := '0';
begin
dut : Kitchen_Timer
port map (clk => clk,
reset => reset,
start => start,
stop => stop,
alarm => alarm);
-- Clock generation
TbClock <= not TbClock after TbPeriod/2 when TbSimEnded /= '1' else '0';
-- EDIT: Check that clk is really your main clock signal
clk <= TbClock;
stimuli : process
begin
-- EDIT Adapt initialization as needed
start <= '0';
stop <= '0';
-- Reset generation
-- EDIT: Check that reset is really your reset signal
reset <= '1';
wait for 100 ns;
reset <= '0';
wait for 100 ns;
-- EDIT Add stimuli here
wait for 100 * TbPeriod;
-- Stop the clock and hence terminate the simulation
TbSimEnded <= '1';
wait;
end process;
end tb;
-- Configuration block below is required by some simulators. Usually no need to edit.
configuration cfg_tb_Kitchen_Timer of tb_Kitchen_Timer is
for tb
end for;
end cfg_tb_Kitchen_Timer;```
#science
@T4V0 Do you understand Proteus?
I have an error in my schematic, and I can't figure out what it is Design the internal block diagram of the Timer 555 circuit. Using the designed circuit
make a pulse width modulated (PWM) amplifier. The amplifier works by
at the output it generates a pulse-width modulated signal of a frequency much higher than
frequency of the signal being amplified and often the frequency of the generated signal is 60
kilohertz if it is an audio amplifier. Depending on the intensity of the input signal,
the mean value of the generated signal at the output changes. By using
of the low-pass filter, a signal is obtained which is an amplified version of the input.
The functionality of the amplifier can be demonstrated by applying a sinusoidal signal at the input
@dejo I don't think this is going to work properly. If I understood correctly your alarm is going to start "alarming" (maybe ringing would be a better term here) after 10 minutes and reset an hour later. I also don't see a way to input or select the desired time for it to ring.
I would also change the stop signal to be the same as the reset (lookup alias) and remove the synchronous stop inside the main process. And the testbench is incomplete since it nevers starts nor its timer is set.
@T4V0 Thanks for the answer, but I think I didn't understand you very well, can you send me the code with the modifications so that I know what exactly you mean?
Thank you very much, in advance
can you send me the code with the modifications so that I know what exactly you mean?
I would rather not, as it isn't a good learning experience for you, and would require some time for me to write the code.
Though if you have any questions about my previous answer, feel free to ask me about it.
As a freebie for you, pay attention to the alarming signal, and the condition that has been set: "The device should have buttons/switches to start and stop the timer, as well as to set the desired time interval for the alarm.". If I wanted the alarm to ring after 50 minutes, how would I do that? And what happens when the timer starts?
From the code I see here, the alarm is going to ring 10 minutes after being started, and it won't stop until an hour passes. And it has no way to set a time for it to ring, it always rings after 10 minutes.
And, not only that, the start signal is never set in the testbench, so the timer is never going to begin.
@T4V0 Hello, I've been doing a lot of research on this project these days and I've brought the code to a better level, I hope... But I'm not sure if this simulation...
This is VHDL code:
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Kitchen_Timer is
port (
clk : in std_logic; -- Clock input
reset : in std_logic; -- Reset input
start : in std_logic; -- Start button input
stop : in std_logic; -- Stop button input
adjust_interval_up : in std_logic; -- Button for increasing alarm interval
adjust_interval_down : in std_logic; -- Button for decreasing alarm interval
alarm : out std_logic -- Alarm output
);
end entity Kitchen_Timer;
architecture Behavioral of Kitchen_Timer is
signal count : integer range 0 to 3600000 := 0; -- Adjust range for 1 hour
signal alarming : std_logic := '0';
signal alarm_interval : integer range 600 to 3600000 := 600; -- Adjust range for 1 hour
@dejo This is much better, but there is still some room for improvement.
There is a mismatch between your comparisons count and alarm_interval. Here in the code bellow you can see the issue:
if stop = '1' or count = alarm_interval then
count <= 0; -- count is 0 here
end if;
[...]
alarming <= '1' when count >= alarm_interval else '0'; -- This condition is never true due to count always being 0 or smaller the alarm_interval.
alarm <= alarming;
As it is right now, the alarming signal is never going to be '1'. It is best to split the comparison and write to alarming directly:
if stop = '1' then
count <= 0;
alarming <= '0';
end if;
if count = alarm_interval then
alarming <= '1';
end if;
[...]
alarm <= alarming;
As for the testbench, you should set the start and unset it only after the alarming is '1', and test if alarming is working after adjusting the timer:
stimuli : process
begin
-- Reset generation
reset <= '1';
wait for 20 us; -- Adjust delay to fit the new clock period
reset <= '0';
-- Add your stimuli and test cases here
-- For example:
start <= '1';
stop <= '0';
wait for 620 us; -- Wait until alarm is alarming
start <= '0'
stop <= '1';
adjust_interval_up <= '1';
wait for 1 us; -- Increment the timer by a minute
start <= '1';
stop <= '0';
adjust_interval_up <= '0';
wait for 1220 us; -- Wait until the alarm is alarming
start <= '0';
stop <= '1';
adjust_interval_down <= '1';
wait for 1 us; -- Decrement the timer by a minute
start <= '1';
stop <= '0';
adjust_interval_down <= '0';
wait for 620 us; -- Wait until the alarm is alarming
start <= '0';
stop <= '1';
wait for 20 us;
-- ...
-- Stop the clock and hence terminate the simulation
TbSimEnded <= '1';
wait;
end process;
I suggest changing the 100 ms time slices you use in the timer to a minute instead. That way your simulation time could be much quicker (though you would also have to change the testbench delays).
@T4V0 I
In the meantime, I worked on improving the code.
VHDL code:
llibrary ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Kitchen_Timer is
port (
clk : in std_logic; -- Clock input
reset : in std_logic; -- Reset input
start : in std_logic; -- Start button input
stop : in std_logic; -- Stop button input
adjust_interval_up : in std_logic; -- Button for increasing alarm interval
adjust_interval_down : in std_logic; -- Button for decreasing alarm interval
alarm : out std_logic -- Alarm output
);
end entity Kitchen_Timer;
architecture Behavioral of Kitchen_Timer is
signal count : integer range 0 to 3600000 := 0; -- Adjust range for 1 hour
signal alarming : std_logic := '0';
signal alarm_interval : integer range 600 to 3600000 := 600; -- Adjust range for 1 hour
begin
process (clk, reset)
begin
if reset = '1' then
count <= 0;
alarm_interval <= 600;
elsif rising_edge(clk) then
if start = '1' then
count <= count + 1;
end if;
if stop = '1' or count = alarm_interval then
count <= 0;
end if;
if adjust_interval_up = '1' then
if alarm_interval < 3600000 then
alarm_interval <= alarm_interval + 600; -- Adjust increment for 1 minute
end if;
count <= 0; -- Reset count when adjusting interval
elsif adjust_interval_down = '1' then
if alarm_interval > 600 then
alarm_interval <= alarm_interval - 600; -- Adjust decrement for 1 minute
end if;
count <= 0; -- Reset count when adjusting interval
end if;
end if;
end process;
alarming <= '1' when count >= alarm_interval else '0';
alarm <= alarming;
end architecture Behavioral;
Testbench:
library ieee;
use ieee.std_logic_1164.all;
entity tb_Kitchen_Timer is
end tb_Kitchen_Timer;
architecture tb of tb_Kitchen_Timer is
component Kitchen_Timer
port (
clk : in std_logic;
reset : in std_logic;
start : in std_logic;
stop : in std_logic;
adjust_interval_up : in std_logic;
adjust_interval_down : in std_logic;
alarm : out std_logic
);
end component;
signal clk : std_logic := '0';
signal reset : std_logic := '0';
signal start : std_logic := '0';
signal stop : std_logic := '0';
signal adjust_interval_up : std_logic := '0';
signal adjust_interval_down : std_logic := '0';
signal alarm : std_logic;
constant TbPeriod : time := 20 ns;
signal TbClock : std_logic := '0';
signal TbSimEnded : std_logic := '0';
begin
dut : Kitchen_Timer
port map (
clk => clk,
reset => reset,
start => start,
stop => stop,
adjust_interval_up => adjust_interval_up,
adjust_interval_down => adjust_interval_down,
alarm => alarm
);
-- Clock generation
TbClock <= not TbClock after TbPeriod/2 when TbSimEnded /= '1' else '0';
clk <= TbClock;
stimuli : process
variable num_ticks : natural;
begin
-- Reset generation
reset <= '1';
wait for 200 us;
reset <= '0';
wait for 200 us;
-- Start the timer
start <= '1';
wait for 500 us;
-- Adjust interval up and down
adjust_interval_up <= '1';
wait for 100 us;
adjust_interval_up <= '0';
wait for 100 us;
adjust_interval_down <= '1';
wait for 100 us;
adjust_interval_down <= '0';
wait for 100 us;
-- Wait for the timer to reach the alarm interval (3600000 clocks)
wait for 72 ms; -- Simulate for the required time
-- Stop the timer
start <= '0';
wait for 300 us;
-- Stop the clock and terminate the simulation
TbSimEnded <= '1';
wait;
end process;
end tb;
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Kitchen_Timer is
port
(
clk : in std_logic; -- Clock input
reset : in std_logic; -- Reset input
start : in std_logic; -- Start button input
stop : in std_logic; -- Stop button input
adjust_interval_up : in std_logic; -- Button for increasing alarm interval
adjust_interval_down : in std_logic; -- Button for decreasing alarm interval
alarm : out std_logic -- Alarm output
);
end entity Kitchen_Timer;
architecture Behavioral of Kitchen_Timer is
signal count : integer range 0 to 60 := 0; -- Adjust range for 1 hour
signal alarming : std_logic := '0';
signal alarm_interval : integer range 1 to 60 := 1; -- Adjust range for 1 hour
begin
process (clk, reset)
begin
if reset = '1' then
count <= 0;
alarm_interval <= 1;
elsif rising_edge(clk) then
if start = '1' then
count <= count + 1;
end if;
if stop = '1' then
count <= 0;
alarming <= '0';
end if;
if count = alarm_interval then
alarming <= '1';
end if;
if adjust_interval_up = '1' then
if alarm_interval < 60 then
alarm_interval <= alarm_interval + 1; -- Adjust increment for 1 minute
end if;
count <= 0; -- Reset count when adjusting interval
elsif adjust_interval_down = '1' then
if alarm_interval > 60 then
alarm_interval <= alarm_interval - 1; -- Adjust decrement for 1 minute
end if;
count <= 0; -- Reset count when adjusting interval
end if;
end if;
end process;
alarm <= alarming;
end architecture Behavioral;
tb_Kitchen_Timer.vhd
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity tb_Kitchen_Timer is
end tb_Kitchen_Timer;
architecture tb of tb_Kitchen_Timer is
signal clk : std_logic := '0';
signal reset : std_logic := '0';
signal start : std_logic := '0';
signal stop : std_logic := '0';
signal adjust_interval_up : std_logic := '0';
signal adjust_interval_down : std_logic := '0';
signal alarm : std_logic;
constant TbPeriod : time := 10 ns;
signal TbClock : std_logic := '0';
signal TbSimEnded : std_logic := '0';
begin
dut : entity work.Kitchen_Timer
port map
(
clk => clk,
reset => reset,
start => start,
stop => stop,
adjust_interval_up => adjust_interval_up,
adjust_interval_down => adjust_interval_down,
alarm => alarm
);
-- Clock generation
TbClock <= not TbClock after TbPeriod/2 when TbSimEnded /= '1' else '0';
-- EDIT: Check that clk is really your main clock signal
clk <= TbClock;
stimuli : process
variable num_ticks : natural;
begin
-- Reset generation
reset <= '1';
wait for 20 ns;
reset <= '0';
wait for 20 ns;
-- Start the timer
start <= '1';
wait for 20 ns;
start <= '0';
stop <= '1';
-- Adjust interval up and down
adjust_interval_up <= '1';
wait for 10 ns;
start <= '1';
stop <= '0';
adjust_interval_up <= '0';
wait for 30 ns;
start <= '0';
stop <= '1';
adjust_interval_down <= '1';
wait for 10 ns;
start <= '1';
stop <= '0';
adjust_interval_down <= '0';
wait for 20 ns;
start <= '0';
stop <= '1';
adjust_interval_up <= '1';
wait for 600 ns;
start <= '1';
stop <= '0';
adjust_interval_up <= '0';
-- Wait for the timer to reach the alarm interval (60 clocks)
wait for 600 ns; -- Simulate for the required time
-- Stop the timer
start <= '0';
stop <= '1';
wait for 100 ns;
-- Stop the clock and terminate the simulation
TbSimEnded <= '1';
wait;
end process;
end tb;
This should be easier to simulate, I've included a simulation done with Questa.
@T4V0 I just now see your messages, thank you..
In the meantime, I made something like this...
What do you think about the specifications that the project requires, should I stick to your code or should I add something from my own code?
Does your simulation correspond to a time of 1 hour and should there be alarming on the simulation?
Vhdl code:
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Kitchen_Timer is
port (
clk : in std_logic; -- Clock input
reset : in std_logic; -- Reset input
start : in std_logic; -- Start button input
stop : in std_logic; -- Stop button input
adjust_interval_up : in std_logic; -- Button for increasing alarm interval
adjust_interval_down : in std_logic; -- Button for decreasing alarm interval
alarm : out std_logic -- Alarm output
);
end entity Kitchen_Timer;
architecture Behavioral of Kitchen_Timer is
signal count : integer range 0 to 3600000 := 0; -- Adjust range for 1 hour
signal alarming : std_logic := '0';
signal alarm_interval : integer range 600 to 3600000 := 600; -- Adjust range for 1 hour
begin
process (clk, reset)
begin
if reset = '1' then
count <= 0;
alarm_interval <= 600;
elsif rising_edge(clk) then
if start = '1' then
count <= count + 1;
end if;
if stop = '1' or count = alarm_interval then
count <= 0;
end if;
if adjust_interval_up = '1' then
if alarm_interval < 3600000 then
alarm_interval <= alarm_interval + 600; -- Adjust increment for 1 minute
end if;
count <= 0; -- Reset count when adjusting interval
elsif adjust_interval_down = '1' then
if alarm_interval > 600 then
alarm_interval <= alarm_interval - 600; -- Adjust decrement for 1 minute
end if;
count <= 0; -- Reset count when adjusting interval
end if;
end if;
end process;
alarming <= '1' when count >= alarm_interval else '0';
alarm <= alarming;
end architecture Behavioral;
Testbench:
library ieee;
use ieee.std_logic_1164.all;
entity tb_Kitchen_Timer is
end tb_Kitchen_Timer;
architecture tb of tb_Kitchen_Timer is
component Kitchen_Timer
port (
clk : in std_logic;
reset : in std_logic;
start : in std_logic;
stop : in std_logic;
adjust_interval_up : in std_logic;
adjust_interval_down : in std_logic;
alarm : out std_logic
);
end component;
signal clk : std_logic := '0';
signal reset : std_logic := '0';
signal start : std_logic := '0';
signal stop : std_logic := '0';
signal adjust_interval_up : std_logic := '0';
signal adjust_interval_down : std_logic := '0';
signal alarm : std_logic;
constant TbPeriod : time := 20 ns;
signal TbClock : std_logic := '0';
signal TbSimEnded : std_logic := '0';
begin
dut : Kitchen_Timer
port map (
clk => clk,
reset => reset,
start => start,
stop => stop,
adjust_interval_up => adjust_interval_up,
adjust_interval_down => adjust_interval_down,
alarm => alarm
);
-- Clock generation
TbClock <= not TbClock after TbPeriod/2 when TbSimEnded /= '1' else '0';
clk <= TbClock;
stimuli : process
variable num_ticks : natural;
begin
-- Reset generation
reset <= '1';
wait for 200 us;
reset <= '0';
wait for 200 us;
-- Start the timer
start <= '1';
wait for 500 us;
-- Adjust interval up and down
adjust_interval_up <= '1';
wait for 100 us;
adjust_interval_up <= '0';
wait for 100 us;
adjust_interval_down <= '1';
wait for 100 us;
adjust_interval_down <= '0';
wait for 100 us;
-- Wait for the timer to reach the alarm interval (3600000 clocks)
wait for 72 ms; -- Simulate for the required time
-- Stop the timer
start <= '0';
wait for 300 us;
-- Stop the clock and terminate the simulation
TbSimEnded <= '1';
wait;
end process;
end tb;
What do you think about the specifications that the project requires, should I stick to your code or should I add something from my own code?
I would stick to my code, your alarm isn't going to work properly due to its comparisons as I mentioned in my previous comments. But if you want to improve the code I modified, you can change the adjust_interval_up and adjust_interval_down buttons to be synchronized to their own states rather than the clock (make their own process with their signals added to the signal sensitivity list and add an extra asynchronous condition to zero the counter on the original process). If you don't make a change like this your alarm is going to take up to an hour to adjust its timer range.
Does your simulation correspond to a time of 1 hour and should there be alarming on the simulation?
Yes, if you have a 1/60 Hertz clock signal. And you must have alarming on the simulation as it is crucial to show that it works.
@T4V0
Is the 1/60 Hz set somewhere or is it set in the code itself?
When you say that I must have an "alarming" signal on the simulation, is it actually this "alarm" signal that is presented on the simulation or?
And, do I need to have count signal in simulation?
Is the 1/60 Hz set somewhere or is it set in the code itself?
You would set that on the testbench or on your synthesis code, but that is unnecessary, I only said that in case if you tested it on a actual FPGA. If you do that on your testbench, it would take a very long time to simulate.
When you say that I must have an "alarming" signal on the simulation, is it actually this "alarm" signal that is presented on the simulation or?
The alarm signal. The "alarming" is when the alarm signal is in a high logic state.
And, do I need to have count signal in simulation?
I wouldn't say it's mandatory, but it is a good addition to the simulation, keep it.
Here, when you change the time interval it's the same as when you turn the knob. So it doesn't last longer when you increase the timer, it just takes longer for it to activate.
This is my .do file (when using Modelsim or Questa, change to the directory with all the .vhd files and the .do file and execute the command do tb.do):
tb.do
#Creates project's library
vlib work
#Compiles project with VHDL93 standard: all files used in the testbench. They should be compiled in order of dependency.
vcom -93 Kitchen_Timer.vhd testbench.vhd
#Simulates (work is the directory, tb_Kitchen_Timer is the entity's name).
#The argument -voptargs="+acc" is necessary to disable signal optimization in Questa.
vsim -voptargs="+acc" -t ns work.tb_Kitchen_Timer
#Show waveforms.
view wave
#Add specific signals.
# -radix: binary, hex, dec, unsigned.
# -label: wave's name.
add wave -label "clk" -radix binary /clk
add wave -label "reset" -radix binary /reset
add wave -label "start" -radix binary /start
add wave -label "stop" -radix binary /stop
add wave -label "adjust_interval_up" -radix binary /adjust_interval_up
add wave -label "adjust_interval_down" -radix binary /adjust_interval_down
add wave -label "alarm" -radix binary /alarm
add wave -label "count" -radix unsigned /dut/count
add wave -label "TbClock" -radix binary /TbClock
add wave -label "TbSimEnded" -radix binary /TbSimEnded
#Simulate for 1500 ns.
run 1500ns
# Zoom to fit entire window.
wave zoomfull
write wave wave.ps