Dff3 filter added to irc inputs.

[fpga/rpi-motor-control.git] / pmsm-control / dff3.vhdl

diff --git a/pmsm-control/dff3.vhdl b/pmsm-control/dff3.vhdl
new file mode 100644 (file)
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--- /dev/null
+++ b/pmsm-control/dff3.vhdl
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+library ieee;
+use ieee.std_logic_1164.all;
+use ieee.std_logic_arith.all;
+use ieee.std_logic_unsigned.all;
+use ieee.numeric_std.all;
+use work.lx_rocon_pkg.all;
+
+-- D circuit (filtered)
+
+entity dff3 is
+  port
+       (
+    clk_i   : in std_logic;
+    d_i     : in std_logic;
+    q_o     : out std_logic
+  );
+end dff3;
+
+architecture behavioral of dff3 is
+       signal d_3r   : std_logic;
+       signal d_2r   : std_logic;
+       signal d_r    : std_logic;
+       signal data_s : std_logic;
+
+       -- XST attributes
+       --potlaceni duplikace klupnych obvodu ve fazi optimalizace
+       --attribute REGISTER_DUPLICATION : string;
+       --attribute REGISTER_DUPLICATION of d_3r : signal is "NO";
+       --attribute REGISTER_DUPLICATION of d_2r : signal is "NO";
+       --attribute REGISTER_DUPLICATION of d_r  : signal is "NO";
+       
+       attribute syn_keep : boolean;
+       attribute syn_keep of d_3r : signal is true;
+       attribute syn_keep of d_2r : signal is true;
+       attribute syn_keep of d_r : signal is true;
+       
+begin
+  q_o <= data_s;
+
+seq:
+       process
+       begin
+    wait until clk_i'event and clk_i = '1';
+               if d_3r = d_2r and d_2r = d_r then
+                       data_s <= d_3r;
+               end if;
+
+               d_3r <= d_2r;
+               d_2r <= d_r;
+               d_r  <= d_i;
+  end process;
+
+end behavioral;