Added rotary decoder and simple controller

2016-05-23 19:22:33 +02:00
parent 16b7cc71ee
commit bc78a40708
10 changed files with 409 additions and 143 deletions
--- a/rotary.vhd
+++ b/rotary.vhd
@@ -0,0 +1,65 @@
+-----------------------------------------------------------------------------
+--
+-- Decoder für Drehgeber
+--
+-----------------------------------------------------------------------------
+ 
+library IEEE;
+use IEEE.STD_LOGIC_1164.ALL;
+ 
+entity rotary_dec is
+    Port ( clk      : in std_logic;         -- Systemtakt
+           A        : in std_logic;         -- Spur A
+           B        : in std_logic;         -- Spur B
+           up_down  : out std_logic;        -- Zaehlrichtung
+           ce       : out std_logic;        -- Clock Enable
+           error    : out std_logic);       -- illegaler Signalübergang
+end rotary_dec;
+ 
+architecture Behavioral of rotary_dec is
+ 
+signal a_in, b_in, a_old, b_old: std_logic;
+ 
+begin
+ 
+-- Abtastung und Verzoegerung der Quadratursignale
+ 
+process(clk)
+begin
+  if rising_edge(clk) then
+    a_old <= a_in;
+    a_in  <= A;
+    b_old <= b_in;
+    b_in  <= B;
+  end if;
+end process;
+ 
+-- Dekodierung der Ausgaenge
+ 
+process(a_in, b_in, a_old, b_old)
+variable state: std_logic_vector(3 downto 0);
+begin
+  state := a_in & b_in & a_old & b_old;
+  case state is
+    when "0000" => up_down <= '0'; ce <= '0'; error <= '0';
+    when "0001" => up_down <= '1'; ce <= '1'; error <= '0';
+    when "0010" => up_down <= '0'; ce <= '1'; error <= '0';
+    when "0011" => up_down <= '0'; ce <= '0'; error <= '1';
+    when "0100" => up_down <= '0'; ce <= '1'; error <= '0';
+    when "0101" => up_down <= '0'; ce <= '0'; error <= '0';
+    when "0110" => up_down <= '0'; ce <= '0'; error <= '1';
+    when "0111" => up_down <= '1'; ce <= '1'; error <= '0';
+    when "1000" => up_down <= '1'; ce <= '1'; error <= '0';
+    when "1001" => up_down <= '0'; ce <= '0'; error <= '1';
+    when "1010" => up_down <= '0'; ce <= '0'; error <= '0';
+    when "1011" => up_down <= '0'; ce <= '1'; error <= '0';
+    when "1100" => up_down <= '0'; ce <= '0'; error <= '1';
+    when "1101" => up_down <= '0'; ce <= '1'; error <= '0';
+    when "1110" => up_down <= '1'; ce <= '1'; error <= '0';
+    when "1111" => up_down <= '0'; ce <= '0'; error <= '0';
+    when others => null;
+  end case;
+end process;
+ 
+end Behavioral;
+