How can I find out basic information about what an IC does, if it isn't clear by context and google doesn't reveal anything useful?
From what I was able to determine online, the CXM4015R was used by Sony in some PlayStation 2 and 3 consoles, and appears to do something related to analog video generation (possibly a DAC of some sort). I wasn't able to find any references to its use anywhere else, suggesting that this part may have been produced by Sony exclusively for this application. This means that information on the part will be hard or even impossible to find — as the only customer for this chip was internal, Sony may not have ever written a datasheet for the part at all.

http://psx-core.ru/forum/4-1249-3 (Russian language forum discussing PS2 modding) has what appears to be a partial schematic of the PS2, which includes a pinout for this chip.