Changes between Initial Version and Version 1 of AdderVbe

Timestamp:

Apr 7, 2007, 11:21:44 PM (17 years ago)

Author:

anonymous

Comment:

--

AdderVbe

@@ +1 @@
+{{{
+-- Additionneur 4 bits avec report entrant et sortant
+
+ENTITY  adder IS
+  PORT (
+    i0          : IN  BIT_VECTOR(3 DOWNTO 0);
+    i1          : IN  BIT_VECTOR(3 DOWNTO 0);
+    q           : OUT BIT_VECTOR(3 DOWNTO 0);
+    cin         : IN  BIT;
+    cout        : OUT BIT;
+    vdd         : IN  BIT;
+    vss         : IN  BIT
+    );
+END  adder;
+
+ARCHITECTURE vbe OF adder IS
+
+  SIGNAL carry : BIT_VECTOR(4 DOWNTO 0) ;
+
+BEGIN
+
+carry(0) <= cin;
+carry(4 DOWNTO 1) <= ( ( i1(3 DOWNTO 0)    AND i0(3 DOWNTO 0) )    OR
+                       ( i0(3 DOWNTO 0)    AND carry(3 DOWNTO 0) ) OR
+                       ( carry(3 DOWNTO 0) AND i1(3 DOWNTO 0) )    ) ;
+q       <= i0 XOR i1 XOR carry(3 DOWNTO 0) ;
+cout    <= carry(2);
+
+END;
+}}}