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•Whens= 1,x1outputs the value ofy, andx0outputs LOW.TODO (pre-lab): Fill in a truth table for the demultiplexer.syx0x1000110111
TODO (pre-lab): Provide a circuit diagram for a 1-to-2 demultiplexer.Your diagram should use specific gates, it should NOT be the symbol shown below.The symbol for a 1-to-2 demultiplexer looks like the opposite of a multiplexer:In the previous lab, you saw that you could make a 1-of-4 multiplexer out of three 1-of-2 multiplexers.TODO (pre-lab): Provide a diagram of how you could make a 1-to-4 demultiplexer using 1-to-2 demulti-plexers (the symbol shown above).Your 1-to-4 demultiplexer will have 4 outputs:x0,x1,x2, andx3. The table belowshows which output returns the value ofyfor different values ofselect1andselect0. Your diagrammustagree with the table.select1select0output that returns y00x001x110x211x32DemultiplexersTODO: Using the circuit diagram from the third TODO of your prelab, implement a 1-to-2demultiplexer on the Magic Box. Leave enough room on your breadboard to wire up a multiplexerfor the next part of this lab. Verify that it works as anticipated and then show it to your TA.2
Next, you will be implementing a multiplexer-demultiplexer scheme on the Magic Box.The instructions below detail this process:1. Turn off the power to the Magic Box while wiring.2.Wire up a1-of-2 multiplexer chip (LS157) next to your demultiplexer. Connectpower,ground, and theenableinput. (Remember from Lab 3 thatenableshould below.) Also connect one pair of inputs,aandb, to two switches.3.Connect the twoselectinputs by wiring thesinput of the demultiplexer chip to thesinput of the multiplexer. Now,the multiplexer and demultiplexer share the same select signal.4.Next, connect theoutoutput of the multiplexer to theyinput of the demultiplexer. The multiplexer and demultiplexershould now be connected as shown in this diagram:5. Verify that your mux-demux scheme works as expected by trying out different combinations of