Yeah, that one would have had me going in circles and up the walls for days as well, I bet. If I were ever to solve it. I bet I would have given up on it...
I think the problem with this kind of stuff, as with for instance STC microcontrollers and other semiconductors from China, is that either documentation is scant to begin with, or it's not properly maintained, and/or it's only made available in Chinese (which I sadly can't read). For these reasons I find myself selecting components from reputable Western suppliers for the most part. There are exceptions of course!