AnsweredAssumed Answered

Help on AD5781

Question asked by hyrsut on Mar 13, 2013
Latest reply on Mar 14, 2013 by hyrsut

Hello,

 

I've to make working an AD5781 with a Spartan 6 FPGA. I'd like to control it using a simple VHDL driver and not a hudge SPI one but the dac doesn't work. I put a part of my vhdl driver as you can take a look and tell me what's wrong. Thanks in advance.

 

-- Data_to_send is "0" & "001" & "011111111110111000" & "11" (23 downto 0)

-- Sclk_temp is at 100KHz

 

sending_data : process(Data_to_send, Sclk_temp)

variable i : integer :=23;

begin

 

CLR  <= '1';

LDAC <= '0';

 

Sclk <= Sclk_temp;

 

if rising_edge(Sclk_temp) then

   

    if i>=0 then

    Sync <= '0';

    SDin <= data_to_send(i);

    end if;

   

i:=i-1;

       

        if i<-1 then

        Sync <= '1';

            if i<-2 then

            i:=23;

            end if;

       

        end if;

         

end if;

    

end process sending_data; 

Outcomes