|FROM ||Ruben Safir
|SUBJECT ||Subject: [LIU Comp Sci] Gates HW problems
|From owner-learn-outgoing-at-mrbrklyn.com Sat Dec 13 23:23:19 2014
Received: by mrbrklyn.com (Postfix)
id 55EEA16115D; Sat, 13 Dec 2014 23:23:19 -0500 (EST)
Received: by mrbrklyn.com (Postfix, from userid 28)
id 3F09D161163; Sat, 13 Dec 2014 23:23:19 -0500 (EST)
Received: from mailbackend.panix.com (mailbackend.panix.com [18.104.22.168])
by mrbrklyn.com (Postfix) with ESMTP id 511D216115D
for ; Sat, 13 Dec 2014 23:23:17 -0500 (EST)
Received: from panix2.panix.com (panix2.panix.com [22.214.171.124])
by mailbackend.panix.com (Postfix) with ESMTP id 6261113E40;
Sat, 13 Dec 2014 23:23:16 -0500 (EST)
Received: by panix2.panix.com (Postfix, from userid 20529)
id 2328433C87; Sat, 13 Dec 2014 23:23:16 -0500 (EST)
Date: Sat, 13 Dec 2014 23:23:16 -0500
From: Ruben Safir
Cc: Samir Iabbassen
Subject: [LIU Comp Sci] Gates HW problems
Content-Type: text/plain; charset=us-ascii
User-Agent: Mutt/1.5.23 (2014-03-12)
I can't find my note on the gates problem from the review and there IS
not notes of logic functions. The way Manesh answered the problem seemd
logical, and it returned logical outputs according to the logics table
Consider following scenario.
A system used 3 switches A, B and C; a combination of switches
whether an alarm, X, sounds: If switch A or switch B are in the ON
position and if switch C is in the OFF position then a signal to sound
alarm, X is produced.
1. Establishing the truth table of the circuit.
A B C F
0 0 0 0
0 0 1 0
0 1 0 1
0 1 1 0
1 0 0 1
1 0 1 0
1 1 0 1
1 1 1 0
2. Determine output functions X= f(A,B,C)
(A+B) * C' = F
which would be seemingly be correct. But the review had an answer like
F(A,B,C) = A'BC' + AB'C' + A'B'C'
which I would think is just crazy, but both functions are equal
That, if of itself is a weird property of bollean math, that is, if you
set F = 1 (True), all of the combinations of a truth table, 'or'
together, solves for the function of F
But I can't find this material in any of the online notes, or any of my
hand notes, or in the text, or even in the ancilary texts that the
slides came from.
I did find this page, so I want to share it from you...
This seems to cover more of the material for this section of the final
plus some additional material which is closely related.
My question is, how did we build this into a logic gate diagram?