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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity foo is
end entity;
architecture fum of foo is
signal ia: std_logic_vector(15 downto 0);
signal clock: std_logic:='0';
signal cw: unsigned(15 downto 0):=(others => '0');
begin
-- counter and cw are converted to UNSIGNED to use numeric_std "+"
CTR: process (clock)
variable counter : unsigned (15 downto 0) := x"0000";
variable op : std_logic_vector (7 downto 0);
begin
if clock'event and clock='1' then
op := std_logic_vector(cw (15 downto 8));
-- This if statement is misbehaving
if (op = x"20") then
counter := counter + cw (7 downto 0);
end if;
counter := counter + 2;
ia <= std_logic_vector(counter);
end if;
end process;
CLK: process
begin
if Now <= 200 ns then
wait for 10 ns;
clock <= not clock;
else
wait;
end if;
end process;
STIMULUS:
process (clock)
begin
if clk'event and clock = '1' then
if Now = 110 ns then
cw <= X"200F";
else
cw <= (others => '0');
end if;
end if;
end process;
end architecture;
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