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I have a homework assignment where I'm supposed to use 4:1 multiplexers to select from one of four logic functions in Logisim. However, my only experience with multiplexers in Logisim up to this point was designing a circuit using 2:1's and passing the output of the multiplexer to the output of the circuit

So how do I use a multiplexer to select a logic function? Do I use a splitter at the multipexer's output? Do I set the data bits in Logisim to 4?

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I don't know how to code...

RTL? you could use a case statement. Does it specify how many selection bits to use? you need 2 selection bits for 4 inputs, but if it explicitly states 4 selection bits, it is probably trying to teach you about one-hot encoding... maybe, or possibly unused inputs.

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  • \$\begingroup\$ Sorry, I meant that my only experience with multiplexers in Logisim was designing a circuit using 2:1's and passing the output of the multiplexer to the output of the circuit. \$\endgroup\$ – moonman239 Jun 13 '18 at 0:36
  • \$\begingroup\$ It's the same process for 4:1, just that you have a decode/selection for 0,1,2,3, instead of just 0,1. You need at least 2 bits for selection. "00" for 0, "01" for 1, "10" for 2, "11" for 3. (or the aforementioned one-hot scheme using 4 bits). \$\endgroup\$ – CapnJJ Jun 13 '18 at 1:39

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