| 1 | library ieee; |
| 2 | |
| 3 | use ieee.std_logic_1164.all; |
| 4 | use ieee.std_logic_unsigned.all; |
| 5 | |
| 6 | entity heartbeat is |
| 7 | generic ( |
| 8 | divider : std_logic_vector(31 downto 0) := X"01F78A40" |
| 9 | ); |
| 10 | |
| 11 | port ( |
| 12 | clk_i : in std_logic; |
| 13 | nrst_i : in std_logic; |
| 14 | led2_o : out std_logic; |
| 15 | led3_o : out std_logic; |
| 16 | led4_o : out std_logic; |
| 17 | led5_o : out std_logic |
| 18 | ); |
| 19 | |
| 20 | end heartbeat; |
| 21 | |
| 22 | architecture rtl of heartbeat is |
| 23 | begin |
| 24 | |
| 25 | process(clk_i, nrst_i) |
| 26 | variable counter : std_logic_vector(31 downto 0); |
| 27 | variable state : std_logic := '0'; |
| 28 | begin |
| 29 | |
| 30 | if (clk_i'event AND clk_i = '1') then |
| 31 | if nrst_i = '0' then |
| 32 | counter := (others => '0'); |
| 33 | else |
| 34 | led5_o <= state; |
| 35 | led2_o <= state; |
| 36 | led4_o <= not state; |
| 37 | led3_o <= not state; |
| 38 | counter := counter + 1; |
| 39 | if counter = divider then |
| 40 | state := not state; |
| 41 | counter := (others => '0'); |
| 42 | end if; |
| 43 | end if; |
| 44 | end if; |
| 45 | end process; |
| 46 | end architecture; |