All 8051 controllers can waste a large number of i/o pins to control external memory chips.

It always seems wiser to select an 8051 variant that has sufficient internal memory. Then you do not waste all those i/o pins.

Many (but not all) eeprom chips will be pin-compatible with say a 62256 SRAM chip. So you could simply replace the chip in a 62256 design. Of course the eeprom will be read-only.

Life would become very complicated if you want to ever write to the eeprom.

IMHO, the simplest method of using an external r/w eeprom chip is via I2C or SPI.

You also have the ability to write to the NXP flash memory at run-time, so if your eeprom needs are small, you could use part of the flash memory.

As with any project, quoting some approximate requirements makes everyone's life easier. e.g. 1k eeprom, 500000us acceptable write time, 1us acceptable read time.

David.