Question

Create a new architecture for ripple_counter (below) called beh_mod10cnt that changes the behavior to a modulo-10 ripple counter.

The ripple counter entity

entity ripple_counter is
 generic (n : natural := 4);
 port ( clk : in std_logic;
        clear : in std_logic;
        dout : out std_logic_vector(n-1 downto 0)
 );
end ripple_counter;

The ripple counter architecture

architecture arch_rtl of ripple_counter is
signal clk_i : std_logic_vector(n-1 downto 0);
signal q_i : std_logic_vector(n-1 downto 0);

begin
        clk_i(0) <= clk;
        clk_i(n-1 downto 1) <= q_i(n-2 downto 0);

        gen_cnt: for i in 0 to n-1 generate
                dff: process(clear, clk_i)
                begin
                        if (clear = '1') then
                                q_i(i) <= '1';
                        elsif (clk_i(i)'event and clk_i(i) = '1') then
                                q_i(i) <= not q_i(i);
                        end if;
                end process dff;
        end generate;
        dout <= not q_i;
end arch_rtl;

Answer 1