vvv A Unique Approach to Digital Gates.
Initial Digital Gate Concepts.
Most textbooks present the basic concepts of 0 and 1 inputs,
using a Truth Table to indicate the output results.
Forget the 0s and 1s approach for now,
Because there really is A MUCH better way.
vvv Consider nicknaming the And Gate as the Only Gate.
Even though the method of the truth table has been the Standard for
many years, and does illustrate the basic concept of
when either the AND Gate or the OR Gate is active, it
is extremely cumbersome when it comes time to evaluate
either of those gate conditions. This is especially
true when there are multiple inputs to deal with. Here
we only have 4 conditions, due to the fact that there
are only 2 inputs, for 4 possible states. but if
we have 3 inputs, for 8 possible states, or 5
inputs, for 32 possible states, a truth table gets
unwieldy in a hurry. What if we had an AND Gate with
9 Inputs? Not only would that require a Truth Table
with 512 possibilities, the evaluation process for
those variables becomes e e e Well, you get the picture.
Consider this simple fact about an AND Gate. No matter
how many inputs there are, there is actually only ONE
possible condition for an active gate. I suggest the
nickname The ONLY Gate , because there is only that
one time, out of all those possible combinations that
the AND Gate will go active. Now we're suddenly making
things much simpler and therefore much easier.
+ !
vvv Consider nicknaming the Or Gate as the Any Gate:
Now consider this simple fact about an OR Gate. No
matter how many inputs there are, the gate will go
active ANY time ANY one of the control inputs meet the
right state or condition. You should be able to see why
I suggest the nickname The ANY Gate , because of those
multitude of input possibilities that can make that
gate go active.
Now, are you ready for this? If you look
closely at what we have just said, and
compare all of those possibilities of the OR
Gate input controls, v.s. what it will take to
make the OR Gate go active, you will see that
it is a mirror image of the AND Gate.
Think of it this way, even with the OR Gate,
there is ONLY ONE TIME that the OR Gate will
NOT go active.
+ !