--State Machine using VariableENTITY fsm2 ISPORT(clock,x : IN BIT; z : OUT BIT);END fsm2;-------------------------------------------------ARCHITECTURE using_wait OF fsm2 ISTYPE state_type IS (s0,s1,s2,s3);BEGINPROCESSVARIABLE state : state_type := s0;BEGINWAIT UNTIL (clock'EVENT AND clock = '1');CASE state ISWHEN s0 => IF x = '0' THENstate := s0;z <= '0';ELSEstate := s2;z <= '1';END IF;WHEN s2 => IF x = '0' THENstate := s2;z <= '1';ELSEstate := s3;z <= '0';END IF;WHEN s3 => IF x = '0' THENstate := s3;z <= '0';ELSEstate := s1;z <= '1';END IF;WHEN s1 => IF x = '0' THENstate := s0;z <= '0';ELSEstate := s2;z <= '0';END IF;END CASE;END PROCESS;END using_wait;