What's wrong with the Philips documentation?
As far as I know there are no second sources for this chip, so I doubt that other documentation exists.

I have been experimenting with this chip a long time ago. I could share code with you, but I don't think it would do you any good for it was for a 6800 (sorry guys, I'm not married to the 8052 ;-)

Reading the Analog inputs is just a matter of writing a control word to it, and then read the channel. The trick is that the conversion is done while another reading is made. This means that you will read garbage the first time.
The DAC is very simple. Write the byte to the device and bingo!

Again, it is a very long time ago for me. But I can't remember ever running into trouble with it.

Happy programming