in my hardware i am using atmel 89c55 microcontroller. it has 20k on chip rom with address ranging from 0000h to 4fffh. i have written one code in assembly language. its size is around 32kb.is it possible that i place 20k of the code in microcontroller on chip rom while the rest of 12k in external eeprom of size say 64k.if possible please guide me how this eeprom will be connected to the microcontroller. what will be the connection for EA,PSEN pins of microcontroller and CE,OE pin of 64k eeprom.is any memory addressing required for the eeprom.