multiplexer - On-the-fly routing of digital and analog signals using unbuffered analog crosspoint arrays?

The issue I have is strongly related to a question which was asked over here. Unfortunately I did not find the answer I was looking for. Digging a bit more I've came across a class of IC's named unbuffered analog crosspoint arrays.

What I would like to know is if an unbuffered analog crosspoint array IC would allow for:

• bidirectional data flow Xn to Yn


• analog signal passthrough with virtually no noise injection up to, let's say, 12-bit resolution


• digital signal passthrough compatible with I2C & SPI & UART

The one IC that I came across is ADG2128 but I'm not sure if it fits the criterias listed above.

I'm well aware that the problem might be solvable via a PLD (be it FPGA or CPLD), but I have no experience whatsoever hardware or firmware (VHDL) wise when it comes to such devices. Implementing an I2C slave altogether with a biderectional crosspoint array is no easy task for a beginner. Thus, a ready-to-go, already made IC would be a good kick-start.

Answer

bidirectional data flow Xn to Yn

It looks "configurably bidirectional": so you can route Xn to Yn, or Yn to Xn, but you have to pick which direction you want in advance.

analog signal passthrough with virtually no noise injection up to, let's say, 12-bit resolution

Bits aren't the most appropriate measure for noise levels in analog signals. You need to use signal-to-noise ratio (SNR) in decibels. 12 bits corresponds to a SNR of at least 72db. This device only guarantees up to 63db crosstalk between adjacent channels, so that may be a problem.

digital signal passthrough compatible with I2C & SPI & UART

Lack of true bidirectionality will be a problem here for I2C. The others ought to work for normal speeds.

I'm well aware that the problem might be solvable via a PLD (be it FPGA or CPLD), but I have no experience whatsoever hardware or firmware (VHDL) wise when it comes to such devices. Implementing an I2C slave altogether with a biderectional crosspoint array is no easy task for a beginner. Thus, a ready-to-go, already made IC would be a good kick-start.

The analog side of this cannot be done with a programmable digital logic device.