Design Of Access Control System Based On CPLD

With higher values being placed on security and privacy,high technology,high security and low cost is the development trend of Access Control System.Access Control System based on CPLD has the adventages such as short develop cycle,designing flexibility,lower cost,higher reliability and higher integration.This system uses a password key instead of physical one,so the key can be modified whenever needed.In such a system,operations are convenient,cards are no longer needed,cost and power cost are low,security and confidentiality are well.The system can be applied in confidential departments,such as banks,hotels,engine rooms,armory confidential rooms,offices,the intelligent communities and factories.This paper elaborated the concept,background,applied fields and developping orientation of the Access Control System and CPLD,then accomplished a 4-bits password Access Control System.The system is composed by the decoder,shift register,comparing module,couting module and controlling module,and it is an alarmable system with a 15 keys keyboad(digits0?9,A?C,ENT,CLR).With the aid of Verilog programme,this paper simulated all the modules mentioned above,and then designed the whole system.Simulation results shows that when the password is correct,the door will be open;when the password is incorrect,the door will be closed,and the error information will be given,when the error times added up to 3,there will be an alarm;people can push reset key to cancel the alarm.