I am looking for a IC that will read the high and low state of 8 or more digital signals at the same time and output a decimal value to a micro, either via a SPI or IC2 serial interface.
A decimal value? Can you explain what you mean better your post doesn't quiet make sense. Do you not have enough I/O lines on your micro controller? SPI uses almost as many I/O lines as you're talking about, there'd be very little gain.
By a decimal value I mean a 0 to 255 if 8 bit or 0 to 1024 if 10bit, etc..
This value would be based on the what inputs where high or low. Example:- If only input 0 and 7 are high it sends the value 129 to the micro via SPI or IC2 interface.
The micro has to control many other things and read many inputs. I just do not have the I/O to be using up 8 pins just for this one thing.
Hunt around for a few more days if you have the time or energy, you may find more capable chips, or at least alternatives from other makers, if nothing else it will give you more than one supplier to work with.