I am working on a project in which a reader communicates with Client through RS232 communication. Because of some customer reasons, the thin Client is rebooted and the system restarts. At that moment, Thin client generates a signal ( may be part of program running inside thin client we don’t know ) on RS232 line and this signal reaches the Rx of P89V51RD2FBC controller and controller automatic goes in programming mode. In P89C51RD2 it requires the pin to be made high for programming and after programming it has to be brought to low. In P89V51RD2FBC, the programming mode is shifted by the frequency signal received on the pins. Any suggestions for this problem ? Has anyone faced this problem ?