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A.“ n. Fig. 34 Recall from the previous lesson that inverting the
inputs and output gave the OR function using
AND gates and the AND function using OR gates.
In the same way, NOR and NAND functions are
shown in Fig. 35 providing opposite functions.
The circuits in 35a and 3—5b would be constructed
using four NAND or four NOR gates respectively
including the inverters. Note that if comple
mentary inputs A and B were available o_n1y two gates ﬁe required to give outputs Y= A—+B and
Y = AB for each Circuit. ‘4qu
it”)
Ylﬁ (b) Fig. 35 From Fig. 35 also it follows that a NOR gate can
be used for an AND operation with inverted inputs
and a NAND gate can be used to perform the OR
operation with inverted inputs. Note that if the
last inverter were eliminated from each circuit,
the outputs would be X = A+B and X = AB,
giving the OR and AND functions. Tables 36 and
37 Show inputs and outputs for the circuits in
Fig. 35. INPUTS OUTPUTS INVERTED Table 36 NAND/NOB Logic Gates 33 INPUTS OUTPUTS INVERTED — 0
0
0
1 Table 37 The equivalency of gates is tabulated in Table 38
on the following page along with a statement of
the logic function, truth table, switch analogy and
stande symbology. Exercise Procedure D 3.a)Connect the logic Circuit shown in Fig. 36a. Cl b) Turn on the trainer power. [I c) Record the inputs and outputs in truth
table of Fig. 36b. I'M The table should indicate the operation of an
AND gate; that only when inputs A and B are 1
the output Y will be 1. ...
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 Fall '05
 Myer,B

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