AD7380 vhdl实例

以下是一个简单的AD7380 VHDL实例，用于读取模拟输入数据并输出数字信号：

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;

entity AD7380 is
    Port ( clk : in  STD_LOGIC;
           cs : in  STD_LOGIC;
           sdi : in  STD_LOGIC;
           sdo : out  STD_LOGIC;
           convst : in  STD_LOGIC;
           busy : out  STD_LOGIC;
           data_out : out  STD_LOGIC_VECTOR (15 downto 0));
end AD7380;

architecture Behavioral of AD7380 is
    signal data_in : std_logic_vector(15 downto 0);
    signal clk_div : std_logic := '0';

begin
    sdo <= data_in(15);

    process (clk, cs)
    begin
        if (cs = '0') then
            if rising_edge(clk) then
                if (convst = '1') then
                    clk_div <= not clk_div;
                end if;
            end if;
        end if;
    end process;

    process (clk_div)
    begin
        if (clk_div = '1') then
            if (convst = '1') then
                data_in <= "0000000000000000";
            elsif (convst = '0') then
                data_in <= data_in(14 downto 0) & sdi;
            end if;
        end if;
    end process;

    process (clk)
    begin
        if (rising_edge(clk)) then
            if (cs = '0') then
                if (convst = '1') then
                    busy <= '1';
                else
                    busy <= '0';
                end if;
                if (convst = '0') then
                    data_out <= data_in(14 downto 0);
                end if;
            end if;
        end if;
    end process;

end Behavioral;

这个实例是一个基本的SPI接口，它通过AD7380 ADC芯片读取模拟输入数据，并将其转换为数字信号。在该实例中，clk信号用于时钟，cs信号用于选择芯片，sdi信号用于串行数据输入，sdo信号用于串行数据输出，convst信号用于启动ADC转换，busy信号指示转换是否完成，data_out信号用于输出数字信号。