lot of applications in the field of consumer electronics, telecommunications, automotive and industrial electronics need non-volatile memory. Because of their byte level flexibility, low I/O pin requirements, low power consumption, small footprint and low cost, Siemens serial EEPROMs are a popular choice for non-volatile storage. This application note provides assistance and source code to ease the design process of interfacing a SLx 24Cxx I2C-bus serial EEPROM to the 8051 controller family, especially to the Siemens C500 8-bit controller family. The source code ( 24Cxx8b.EXE) as well as the datasheets for SLx 24Cxx EEPROMs are also available in the Siemens World Wide site at address: