Can multiple multiplexers use the SAME address lines?

Hi,

So I need to access six ADC devices using a SPI communication protocol. Apart from the SPI pins, I have a START, RESET, DRDY, and CS pin for EACH ADC for which I need to use 3x8:1 demultiplexers and 1x1:8 multiplexer.

I was thinking of maybe associating the SAME address for all the demultiplexers and multiplexer to link to the SAME ADC and was wondering if the same address lines could be used for multiple multiplexers.

So, if I use D4,D5,D6 as the address lines and connect them to the S0,S1,S2 pins of ALL demultiplexers and multiplexer, would setting the output of these pins to one value and enabling all the demultiplexers and multiplexers allow me to communicate with one of the ADCs?

Or do I have to use individual address lines for each multiplexer?

I hope my question is clear and would be really grateful if anyone could help.

I hope my question is clear

Not to me. It would help if you could provide a link to a data sheet of these sensors and a schematic of how you are going to wire them up.

I think what you are trying to do is OK but without a schematic I can't be sure.

Hi Mike,

The configuration I'm thinking of is something along these lines:

|500x167

The output of the first three demux devices goes to the respective inputs of the ADCs and the last one would read the input from each of the ADCs by switching through addresses of the MUX and checking if the DRDY is LOW (Kinda polling).

So, will using the same address bits of D4D5D6 for S0S1S2 for all of the devices at the same time work? I feel like in theory it should but just wanted to confirm.

What chips are these demux chips please, also can you label the connections on the schematic for the chips like you did for the Arduino. Without this information all you have is a box with wires going into it. I would not think you need to connect anything to the Arduino's reset pin to anything, and what pin is START and DRDY on an Arduino?

"So I need to access six ADC devices using a SPI communication protocol." So you need six CS lines then, however you create them - three address lines into a 3 to 8 demux chip would work, with one enable line from the Arduino to let a selected output go low. A shift register would also work, and needs only three lines. The address lines and Start go to all devices in parallel. The Drdy from all devices go back to the Arduino in parallel, maybe with schottky diode for isolation so one can pull the line low without fighting high outputs from the other chips.

If you want more help, we need the ADC chip number.