move all vhd files to src folder

1 files changed, 43 insertions, 0 deletions

diff --git a/src/add1b.vhd b/src/add1b.vhd
new file mode 100644
index 0000000..a2d4068
--- /dev/null
+++ b/src/add1b.vhd
@@ -0,0 +1,43 @@
+LIBRARY ieee;
+USE ieee.std_logic_1164.ALL;
+USE ieee.numeric_std.ALL;
+
+-- full adder entity
+entity add1b is
+  port (
+    A: in std_logic;
+    B: in std_logic;
+    Cin: in std_logic;
+    X: out std_logic;
+    Cout: out std_logic);
+end add1b;
+
+architecture Behavioral of add1b is
+  signal s0: std_logic;
+  signal s1: std_logic;
+  signal s2: std_logic;
+  component half_add
+	port (
+	  A: in std_logic;
+      B: in std_logic;
+      X: out std_logic;
+      Cout: out std_logic);
+  end component;
+begin
+	-- first add A and B with HA
+	add0: component half_add
+    port map (
+      A => A,
+      B => B,
+      X => s0,
+      Cout => s1);
+	-- then add first result with Cin to get final result
+  add1: component half_add
+    port map (
+      A => Cin,
+      B => s0,
+      X => X,
+      Cout => s2);
+	-- calculate Cout by OR-ing the Cout of both half adders
+  Cout <= (s2 OR s1);
+end Behavioral;