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-rw-r--r--fpga/hp_lcd_driver/synchronizer.vhdl26
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diff --git a/fpga/hp_lcd_driver/synchronizer.vhdl b/fpga/hp_lcd_driver/synchronizer.vhdl
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+library IEEE;
+use IEEE.STD_LOGIC_1164.all;
+
+entity synchronizer is
+ generic (stages : natural := 2);
+ port (clk : in std_logic;
+ i : in std_logic;
+ o : out std_logic);
+end synchronizer;
+
+architecture Behavioral of synchronizer is
+ signal flipflops : std_logic_vector(stages-1 downto 0) := (others => '0');
+ attribute ASYNC_REG : string;
+ attribute ASYNC_REG of flipflops : signal is "true";
+begin
+
+ o <= flipflops(flipflops'high);
+
+ clk_proc : process(clk, flipflops, i)
+ begin
+ if rising_edge(clk) then
+ flipflops <= flipflops(flipflops'high-1 downto 0) & i;
+ end if;
+ end process;
+
+end Behavioral;