Test Kit 4-bit Adder

src/t_add4.vhd

@@ -82,6 +82,18 @@ BEGIN  -- tbench
     ci_i <= '0';             -- set a value to input ci_i as a 1-bit value
     WAIT FOR period;         -- values are assigned here
     ASSERT sum_o = X"0" REPORT "Error: sum is not correct !" SEVERITY failure;
+    ASSERT co_o = '0' REPORT "Error: co is not correct !" SEVERITY failure;
+
+    a_i <= "0001";           -- change value of a_i as binary vector value
+    b_i <= "0001";
+    WAIT FOR period;
+    ASSERT sum_o = X"2" REPORT "Error: sum is not correct !" SEVERITY failure;
+    ASSERT co_o = '0' REPORT "Error: co is not correct !" SEVERITY failure;
+
+    a_i <= "0010";           -- change value of a_i as binary vector value
+    b_i <= "0100";
+    WAIT FOR period;
+    ASSERT sum_o = X"6" REPORT "Error: sum is not correct !" SEVERITY failure;
     ASSERT co_o = '0' REPORT "Error: co is not correct !" SEVERITY failure;
     
                              -- prefix B is the default, hence not necessary to write