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<DIV><FONT face=Arial size=2>For any 3 or 4 input logic function just use a
multiplexer IC.</FONT></DIV>
<DIV><FONT face=Arial size=2>A 74xx150 is a 16 to 1 selector/mpx usable for 4
inputs, if 3 inputs are needed there are smaller 8 to 1 ICs
eg 4051, 74151.</FONT></DIV>
<DIV><FONT face=Arial size=2>The select lines are your logic inputs and Q
is your logic out put, the data inputs connect to 1 or 0 depending on your
tables of truth.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>HTH</FONT></DIV>
<DIV><FONT face=Arial size=2>Theo</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=schierld@msoe.edu href="mailto:schierld@msoe.edu">Schierl, Dan</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=synth-diy@dropmix.xs4all.nl
href="mailto:synth-diy@dropmix.xs4all.nl">synth-diy@dropmix.xs4all.nl</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, September 12, 2004 12:22
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [sdiy] an XOR question</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial color=#000000 size=2>Hi list--</FONT></DIV>
<DIV><FONT face=Arial size=2>I have an application I'm working on in which I
need to perform an exclusive OR on 4 inputs. Since I don't think anyone makes
a 4-input XOR, I tried to rig something up using some CMOS chips. My first
attempt was a little too simplistic (i.e. wrong), which I didn't realize until
I'd already wired it into my application. I think my second attempt works
(haven't tried it yet, tho) but i think it might be overkill. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Go here: <A
href="http://people.msoe.edu/~schierld/temp/xor.html">http://people.msoe.edu/~schierld/temp/xor.html</A> to
see my two ideas.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My question is: the second idea is pretty much a
literal definition of an XOR gate, but I wonder if there are any trick ways to
make one of these with fewer chips. Any thoughts you might have would be
appreciated. thanks!</FONT></DIV></BLOCKQUOTE></BODY></HTML>