SPI経由でLTC2426 DACと通信しようとしましたが、失敗しました。今、私は助けを求めています。私のコードが機能しない理由を教えてください。CSDAC は正常に動作し、SCLK が生成されて 32 ビットが送信されますが、それでもタイミングが狂った可能性があります。誰かがコードを修正するのを手伝ってくれたら、とても感謝しています。
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity DAC is
port
(
CLK : in STD_LOGIC;
SCLK : out STD_LOGIC;
MOSI : out STD_LOGIC;
CSDAC : out STD_LOGIC := '1'
);
end DAC;
architecture Behavioral of DAC is
Signal Counter : Integer range 0 to 32 := 0;
Signal CurrentBit : Integer range 0 to 32 := 0;
Signal DataSent : STD_LOGIC := '1';
Constant Data : STD_LOGIC_VECTOR(31 downto 0) := X"0030FFF0";
Signal Slope : STD_LOGIC := '0';
begin
Prescaler : process(CLK)
begin
if rising_edge(CLK) then
if Counter = 5 then
Slope <= not(Slope);
Counter <= 0;
else
Counter <= Counter + 1;
end if;
end if;
end process;
SCLK <= SLOPE;
WriteDac : process(CLK)
begin
if rising_edge(CLK) then
if DataSent = '1' then
if CurrentBit <= 31 then
CSDAC <= '0';
MOSI <= Data(CurrentBit);
CurrentBit <= CurrentBit +1;
else
CSDAC <= '1';
DataSent <= '0';
end if;
end if;
end if;
end process;
end Behavioral;
編集:新しいコード
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity DAC is
port
(
CLK : in STD_LOGIC;
SCLK : out STD_LOGIC;
MOSI : out STD_LOGIC;
DEBUG : out STD_LOGIC := '1';
CSDAC : out STD_LOGIC := '1'
);
end DAC;
architecture Behavioral of DAC is
Signal Counter : Integer range 0 to 6 := 0;
Signal Counter2 : Integer range 0 to 33 := 0;
Signal CurrentBit : Integer range 0 to 33 := 0;
Signal Fixed : STD_LOGIC := '0';
Signal DataSent : STD_LOGIC := '0';
Constant Data : STD_LOGIC_VECTOR(31 downto 0) := X"0FFF0C00";
Signal Slope_last : STD_LOGIC := '0';
Signal Slope : STD_LOGIC := '0';
Signal MSS : STD_LOGIC := '0';
begin
WriteDac : process(CLK)
begin
if rising_edge(CLK) then
if Counter = 5 then
Slope_last <= Slope;
Slope <= not(Slope);
if Slope_last = '1' and Slope = '0' then
if Fixed = '1' then
if DataSent = '0' then
if CurrentBit <= 31 then
CSDAC <= '0';
DEBUG <= '0';
MOSI <= Data(CurrentBit);
CurrentBit <= CurrentBit +1;
else
MOSI <= '0';
CSDAC <= '1';
DEBUG <= '1';
DataSent <= '1';
end if;
end if;
else
if Counter2 <= 31 then
CSDAC <= '1';
DEBUG <= '1';
Counter2 <= Counter2 + 1;
MSS <= not(MSS);
MOSI <= MSS;
else
Fixed <= '1';
MOSI <= '0';
end if;
end if;
end if;
else
Counter <= Counter + 1;
end if;
end if;
end process;
SCLK <= SLOPE;
end Behavioral;
数ビットを送信すると SCLK が回復するため、MOSI をパルスします。最初の SCLK は、mosi をパルスすると約 1.4 mhz で実行され、4.167 mhz に回復します。