help!!how to share the same input port??

[meera83]

m using four demultiplexs(A,B,C,D).
Each demultiplex got 10 outputs
(A0,A1,A2,..A9; B0,B1,B2...B9; C0,C1..C9; D0,D1,D2...D9).

i now want to put (A0,B0,C0,D0) in one node; (A1,B1,C1,D1) in one node;
(A2,B2,C2,D2) in one node and so on..

when i "on" 'A' demultiplex and 'off' 'B,C,D' demultiplexs, the output A should be show out on LED...

i control 'on' and 'off' of the demultiplex at their Vcc part..

but i now facing with a problem that since one node is shared by four input, there seen have interference at lighting the LED between the output should be show..

how should i do if i want to share the input port, but it can give one output when either a chip is 'on'..

 

[Russlk]

You will need a multiplexer for each output that you want to combine. It is not necessary to turn the demultiplexers off and on, just the multiplexers.