Part 1 Block 1 - Logical Operators Flashcards
The components that represent the most fundamental operations are called l_________ g____________.
logic gates
We can combine logic gates in a l____________ c____________ in order to create more complex operations.
logic circuit
List the three basic logic gates that you have learnt so far.
The NOT operation
The AND operation
The OR operation
What is the NOT logic gate also known as?
An inverter
Which logic gate (operation) would we use to ‘flip’ a ‘1’ to a ‘0’ or vice versa?
The NOT logic gate.
If we had a single-bit that we called ‘A’, and ‘A’ is ‘1’, but we wanted to flip that to a ‘0’, what would we call the operation?
NOT A operation
The logic operation AND is analogous to m____________________
multiplication
Most logical operations involve two input values. Complete the AND truth table:
A B A AND B
0 x 0
0 1
1 0
1 1
A AND B
0
0
0
1
The OR operation is akin to a______________
addition
N.B. Do not get this confused with the ‘or’ function in coding!
Boole decided that when using the logical operators in binary, he would only have a 1-bit answer.
We know that in binary 1+ 1 = 10
Boole had to decide how he would represent the answer with only 1-bit.
Did he choose ‘1’ or ‘0’?
1
Complete the OR truth table.
A B A OR B
0 0
0 1
1 0
1 1
A OR B
0
1
1
1
a) Construct the truth table and write a logic expression for B < A.
b) Sketch the equivalent logic circuit.
A AND NOT B
See Evernote TM112/Part1/Block1/Note 3
More complex logic circuits
What do we do to the logic expressions if there is more than one row where the output is 1?
E.g:
A B A == B Logic Expression
0 0 1 NOT A AND NOT B
0 1 0
1 0 0
1 1 1 A AND B
The logic expressions must be combined with the OR operator.
E.g. (NOT A AND NOT B) OR (A AND B)
