library ieee;
use ieee.std_logic_1164.all;

entity adc is
port (
clk : in std_logic;
start : in std_logic;
dout : out std_logic_vector(7 downto 0)
);
end entity;

architecture rtl of adc is

signal count : std_logic_vector(7 downto 0);
signal data_in : std_logic_vector(7 downto 0);
signal state : std_logic_vector(2 downto 0);

begin

process(clk)
begin
if rising_edge(clk) then
case state is
when “000” => — Idle State
if start = ‘1’ then
count ‘0’);
state — Acquisition State
count <= count + 1;
if count = "11111111" then — Wait for 256 cycles
data_in <= some_adc_function(); — Replace with your own ADC function
state — Conversion State
count <= count + 1;
if count = "11111111" then — Wait for 256 cycles
dout <= data_in;
state
state <= "000"; — Reset to Idle State
end case;
end if;
end process;

end architecture;

Here data_in should be assigned to certain ADC Function so as to read the input. But I am confused as to how to initiate this. Could you please help me?

Thank You.

Interested this article and forum

Interested this article and forum

it is correct, you can skip the “r_data” signal.
If you register the input, the synthesizer can put the register in the FPGA pad.
In this case, you have to worry about only the phase of the clock vs ADC data without worrying about the skew of the ADC data bus.

Can you explain why you need this signal?
“signal r_data : std_logic_vector(3 downto 0);”

Can you skip it and feed the input into the output?

“elsif(rising_edge(i_clk)) then
o_data <= i_data;
end if;"

Thanks!

Hello,can you send the testbench of this code?
medine.bolat.287@gmail.com

it depends on the ADC you are interfacing.
You should read the ADC interface timing and implement a test bench that emulate that timing