hello sir/madam, i am practicing in 8051(nxp89c51rd2) micro controller,in that, i interfaced keypad and stored the value given by the keypad in the controller, the value is stored in RAM(30h onwards),as it is a volatile memory it has lost all the input data when power shutdown, is there any nonvolatile memory in the above said microcontroller, or is there any alternative to store the date in the non volatile memory.i wand to store the data in the microcontroller which is given by 4x4 keypad,and it must remain even after power shutdown. thanks in advance