4 files changed, 133 insertions, 67 deletions
diff --git a/full-adder/full-adder.srcs/sim_1/add1b_tb.vhd b/full-adder/full-adder.srcs/sim_1/add1b_tb.vhd
new file mode 100644
index 0000000..18f05eb
--- /dev/null
+++ b/full-adder/full-adder.srcs/sim_1/add1b_tb.vhd
@@ -0,0 +1,72 @@
+library ieee;
+library unisim;
+
+use ieee.std_logic_1164.all;
+use ieee.numeric_std.all;
+use unisim.vcomponents.all;
+
+entity add1b_tb is
+end add1b_tb;
+
+architecture behavioral of add1b_tb is
+component add1b
+port (
+	A: in std_logic;
+	B: in std_logic;
+	Cin: in std_logic;
+	X: out std_logic;
+	Cout: out std_logic);
+end component;
+
+signal A: std_logic;
+signal B: std_logic;
+signal Cin: std_logic;
+signal X: std_logic;
+signal Cout: std_logic;
+signal test_case: std_logic_vector(2 downto 0);
+signal ok: boolean := true;
+
+begin
+	test_port: add1b port map(
+		A => A,
+		B => B,
+		X => X,
+		Cout => Cout,
+		Cin => Cin);
+
+	tb: process
+		variable A_t: std_logic;
+		variable B_t: std_logic;
+		variable Cin_t: std_logic;
+		variable X_t: std_logic;
+		variable Cout_t: std_logic;
+		variable Out_t: std_logic_vector(1 downto 0);
+
+	begin
+		for i in 0 to 7 loop
+			test_case <= std_logic_vector(to_unsigned(i,3));
+			wait for 1 ps;
+	
+			A <= test_case(0);
+			B <= test_case(1);
+			Cin <= test_case(2);
+
+			A_t := test_case(0);
+			B_t := test_case(1);
+			Cin_t := test_case(2);
+
+			X_t := A_t xor B_t xor Cin_t;
+			Cout_t := (A_t and B_t) or (B_t and Cin_t) or (Cin_t and A_t);
+
+			wait for 5 ns;
+			If X /= X_t then
+				OK <= false;
+			end if;
+			if Cout /= Cout_t then
+				OK <= false;
+			end if;
+			wait for 5 ns;
+		end loop;
+		wait; -- stop for simulator
+	end process;
+end;
diff --git a/full-adder/full-adder.srcs/sources_1/add1b.vhd b/full-adder/full-adder.srcs/sources_1/add1b.vhd
new file mode 100644
index 0000000..a2d4068
--- /dev/null
+++ b/full-adder/full-adder.srcs/sources_1/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;
diff --git a/full-adder/full-adder.srcs/sources_1/add4b.vhd b/full-adder/full-adder.srcs/sources_1/add4b.vhd
index 184d360..07e5a22 100644
--- a/full-adder/full-adder.srcs/sources_1/add4b.vhd
+++ b/full-adder/full-adder.srcs/sources_1/add4b.vhd
@@ -2,73 +2,6 @@ LIBRARY ieee;
 USE ieee.std_logic_1164.ALL;
 USE ieee.numeric_std.ALL;
 
--- half adder entity
-entity half_add is
-  port (
-    A: in std_logic;
-    B: in std_logic;
-    X: out std_logic;
-    Cout: out std_logic);
-end half_add;
-
-architecture Behavioral of half_add is
-begin
-  Cout <= (A AND B);
-  X <= (A XOR B);
-end Behavioral;
-
-
-
-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;
-
-
-
-LIBRARY ieee;
-USE ieee.std_logic_1164.ALL;
-USE ieee.numeric_std.ALL;
-
 -- full 4-bit adder entity
 entity add4b is
   port (
diff --git a/full-adder/full-adder.srcs/sources_1/half_add.vhd b/full-adder/full-adder.srcs/sources_1/half_add.vhd
new file mode 100644
index 0000000..d2d340a
--- /dev/null
+++ b/full-adder/full-adder.srcs/sources_1/half_add.vhd
@@ -0,0 +1,18 @@
+LIBRARY ieee;
+USE ieee.std_logic_1164.ALL;
+USE ieee.numeric_std.ALL;
+
+-- half adder entity
+entity half_add is
+  port (
+    A: in std_logic;
+    B: in std_logic;
+    X: out std_logic;
+    Cout: out std_logic);
+end half_add;
+
+architecture Behavioral of half_add is
+begin
+  Cout <= (A AND B);
+  X <= (A XOR B);
+end Behavioral;