migrate from Travis to GHA and rework examples (#78)

* migrate from Travis to GHA

* rework examples

1 files changed, 51 insertions, 0 deletions

diff --git a/examples/icestick/rotate1.vhdl b/examples/icestick/rotate1.vhdl
new file mode 100644
index 0000000..34c7afd
--- /dev/null
+++ b/examples/icestick/rotate1.vhdl
@@ -0,0 +1,51 @@
+architecture rotate1 of leds is
+  signal clk_4hz: std_logic;
+begin
+  process (clk)
+    --  3_000_000 is 0x2dc6c0
+    variable counter : unsigned (23 downto 0);
+  begin
+    if rising_edge(clk) then
+      if counter = 2_999_999 then
+        counter := x"000000";
+        clk_4hz <= '1';
+      else
+        counter := counter + 1;
+        clk_4hz <= '0';
+      end if;
+    end if;
+  end process;
+
+  process (clk)
+    variable count : unsigned (1 downto 0);
+  begin
+    if rising_edge(clk) and clk_4hz = '1' then
+      count := count + 1;
+      if count = 0 then
+        led1 <= '1';
+        led2 <= '0';
+        led3 <= '0';
+        led4 <= '0';
+        led5 <= '1';
+      elsif count = 1 then
+        led1 <= '0';
+        led2 <= '1';
+        led3 <= '0';
+        led4 <= '0';
+        led5 <= '0';
+      elsif count = 2 then
+        led1 <= '0';
+        led2 <= '0';
+        led3 <= '1';
+        led4 <= '0';
+        led5 <= '1';
+      else
+        led1 <= '0';
+        led2 <= '0';
+        led3 <= '0';
+        led4 <= '1';
+        led5 <= '0';
+      end if;
+    end if;
+  end process;
+end rotate1;