Well, I did a search for a 24LC84 and could not find a data sheet anywhere. What size is this part? If it is bigger than 32 kbits, then it probably needs a word size value for mem_off. For your ram_lo data I think you should mask off the upper byte by and'ing MyWordWrite and MyWordRead with 0xFF. Or use the .lowbyte and .highbyte modifiers. In fact, I don't see size definitions for any of your variables. Is mem_off a byte or word variable? Is ram a byte or word array? What are F05 and F10 defined as?