Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

DAC with THDB-ADA on DE2-115

Hi there, I'm working with DAC on the daughter board THDB-ADA. The pin assignments are correct, I believe, but the circuit doesn't seem to be working. Here are my waveforms from ModelSim, can so...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

You can use this to simulate a sine wave 2MHz

signal datax_s : std_logic_vector(13 downto 0);

constant len : integer := 100;

type data_array is array(natural range len-1 downto 0) of std_logic_vector(13 downto 0);

signal datax: data_array := (

"10000000000000","10111101101010","11101100000100","11111111101111",

"11110011110100","11001011001111","10010000000010","01010000111000",

"00011101010111","00000010010001","00000110010000","00101000011000",

"01100000001010","10011111110101","11010111100111","11111001101111",

"11111101101110","11100010101000","10101111000111","01101111111101",

"00110100110000","00001100001011","00000000010000","00010011111011",

"01000010010101","01111111111111","10111101101010","11101100000100",

"11111111101111","11110011110100","11001011001111","10010000000010",

"01010000111000","00011101010111","00000010010001","00000110010000",

"00101000011000","01100000001010","10011111110101","11010111100111",

"11111001101111","11111101101110","11100010101000","10101111000111",

"01101111111101","00110100110000","00001100001011","00000000010000",

"00010011111011","01000010010101","10000000000000","10111101101010",

"11101100000100","11111111101111","11110011110100","11001011001111",

"10010000000010","01010000111000","00011101010111","00000010010001",

"00000110010000","00101000011000","01100000001010","10011111110101",

"11010111100111","11111001101111","11111101101110","11100010101000",

"10101111000111","01101111111101","00110100110000","00001100001011",

"00000000010000","00010011111011","01000010010101","01111111111111",

"10111101101010","11101100000100","11111111101111","11110011110100",

"11001011001111","10010000000010","01010000111000","00011101010111",

"00000010010001","00000110010000","00101000011000","01100000001010",

"10011111110101","11010111100111","11111001101111","11111101101110",

"11100010101000","10101111000111","01101111111101","00110100110000",

"00001100001011","00000000010000","00010011111011","01000010010101"); -- 2MHz

create_signal_process: process(RESET,clockR)

begin

if RESET = '1' then

datax_s <= (others => '0');

elsif rising_edge(clockR) then

datax <= datax(len-2 downto 0) & datax(len-1);

datax_s <= datax(len-1);

end if;

XOUT <= datax_s;

end process;

XOUT (DAC channel A) should be a sinewave 2MHz