522 pages is not that bad. It gets worse when you find out that a lot of stuff doesn´t work as described, because the guy writing the datasheet was using copy paste way too much and the implementation is slightly different. Stuff like references to pins that don´t even exist, default values not being set like they should, and some functions not working at all. Just minor stuff in an overall fine system, but still it takes a lot of time to figure out. This is my experience with a completely different chip, but the manufacturer remains the same.