Thanks, I couldn't remember which datasheet I had seen that in (I've been paging through a lot of different uP datasheets lately). But does that mean that they left out part of the description in the 841 datasheet or that the 1634 is different? Either way, it still doesn't really explain what it does.
I have also noticed numerous errors in Atmel's datasheets. Their web site also has errors, promising features online that are not mentioned in the actual datasheets. There are some things I just can't figure out by reading the documentation alone. I will have to buy the parts and try them.