Via VT1731

Not much chance.
Data sheets are only released via an NDA, which means it will be very hard to get the datasheet unless yoiu are a development partner or a legit firm with a product in mind. Then discussing the device in detail on this forum will be breaking the NDA, so you will get in trouble. I would look for a similar chip from someone like Ti, much more user friendly to deal with.
 
There are quite a few like that, especialy if they are likely to be used in PC's I've found. we use quite a few, some ethernet chips that we have to sign a NDA for are a nightmare to get data and application notes for. I think they are nuerotic about their IP being copied.
 
That's the problem with companies like VIA. They are so hush hush about their chips, one could almost assume they don't want to sell any 🙄. You can ask nicely for the datasheet (I've done it in the past), but getting hold of a supplier who is willing to sell small amounts is nearly impossible.