Architecture Declarations

Architecture declarations describe the operation of the component
Many architectures may exist for one entity, but only one may be active at a time
An architecture is similar to a schematic of the component

ARCHITECTURE behavior1 OF
half_adder IS BEGIN
   PROCESS (enable, x, y)
   BEGIN
   IF (enable = '1') THEN
     result <= x XOR y;
     carry <= x AND y;
   ELSE
     carry <= '0'
     result <= '0';
   END PROCESS;
END behavior1;