+= heartbeat

[raggedstone] / heartbeat / source / heartbeat.vhd

diff --git a/heartbeat/source/heartbeat.vhd b/heartbeat/source/heartbeat.vhd
new file mode 100644 (file)
index 0000000..76f084d
--- /dev/null
+++ b/heartbeat/source/heartbeat.vhd
@@ -0,0 +1,39 @@
+library ieee;
+
+use ieee.std_logic_1164.all;
+use ieee.std_logic_unsigned.all;
+
+entity heartbeat is
+generic (
+       divider : integer := 33000000
+);
+
+port (
+       clk_i : in std_logic;
+       nrst_i : in std_logic;
+       led_o : out std_logic
+);   
+
+end heartbeat;
+
+architecture rtl of heartbeat is
+begin
+
+process(clk_i, nrst_i)
+variable counter : std_logic_vector(31 downto 0);
+variable state : std_logic := '0';
+begin
+
+if (clk_i'event AND clk_i = '1') then
+       if nrst_i = '0' then
+               counter := (others => '0');
+        else
+               led_o <= state;
+               counter := counter + 1;
+               if counter = divider then
+                       state := not state;
+               end if;
+       end if;
+end if;
+end process;
+end architecture;