1)
When asking questions about a specific peripheral chip, please do include a link to the datasheet. The undersigned does not start hunting for a datasheet for a peripheral he does not know because it is mentioned in a post, but if a link is included he usually takes a look just out of curiosity.

2) ALWAYS specify the '51 derivative you are using AND state if you are willing to change. E.g. help for IIC depends very much on which chip is actually used (hardware vs bit-bang). I do recall someone asking about IIC a while ago and bit-bang suggestions were coming out of the woodwork and 10 posts later it was discovered that his chip had hardware IIC.

Erik