since we're on the theoretical, could we use the clock on the bus and multiply it to a usable frequency for the pair? they would be sharing the same clock and would code/decode at the same fixed rate.... it could be interesting to play with and who knows what unused portions exists on other chips in whatever the device is being cooked up... there are other chips but I chose that one because plenty have played with them and the later uses included digital implementations as well, looking a few years back you're likely to find some very simple uses all the way to... let's see what this little chip can do crazy stuff.... It was rattling around in my head I know we used them in some projects many years ago....and it wasn't at all difficult or pricey to do.... like so many things it took forever to get it from the fog of my distant memory to light... so for my part I apologize for taking so long to get my grey matter to move on it... and likely longer to remember what we did...
looks like there are better options for slightly more money these days... all pretty much built in 1 wire solutions..... in any event neat stuff to delve back into but I'm just playing about now btw they lie.... I mean 1 wire active 1 wire ground that's two but ground already exist still.... amazing bidirectional wonder the more you want the pricier they can be!
I would love to implement a shared audio aspect on the signal assigned PBI audio input (that would be so cool!), but only if it were able to be done with a minimum of components since my 1088XEL motherboard project's goal is to build something with a very small footprint. The nice thing about this approach, is that it would still be compatible with the original mono usage, and obviously not require any other spare pins.
Your idea of using the system clock is a good one, and likely PH2 would serve that purpose well (great idea!). I think this would be fun to experiment with and see what is possible. Any suggestions on a good dual channel sample and hold amp that would suit this implementation? Or an all in one chip that also includes the demux aspect as well?