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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity sipo is
port (clk : in std_logic;
in_data : in std_logic;
out_data : out std_logic_vector(1 downto 0));
end entity;
architecture rtl of sipo is
signal mem : std_logic_vector(1 downto 0);
signal ctr : unsigned(0 downto 0);
begin
process (clk) begin
if rising_edge(clk) then
-- This indirection doesn't synthesize correctly.
mem(to_integer(ctr)) <= in_data;
ctr(0) <= not ctr(0);
end if;
end process;
out_data <= mem;
end architecture rtl;
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