Logic Gates And Boolean Algebra Flashcards
1
Q
What is the order of logic gates simplification?
A
- Brackets
- Negation (NOT)
- Multiplication (AND)
- Addition (OR)
2
Q
What are the commutative laws?
A
- A /\ B = B /\ A
- A V B = B V A
3
Q
What are the associative laws?
A
- (A V B) V C = A V (B V C) = A V B V C
- (A /\ B) /\ C = A /\ (B /\ C) = A /\ B /\ C
4
Q
What are the distributive laws?
A
- A /\ (B V C) = (A /\ B) V (A /\ C)
- A V B /\ C = (A V B) /\ (A V C)
5
Q
What are De Morgan’s Laws?
A
¬(A V B) = ¬A /\ ¬B
¬(A /\ B) = ¬A V ¬B
6
Q
What are the AND rules?
A
- A /\ 0 = 0
- A /\ A = A
- A /\ 1 = A
- A /\ ¬A = 0
7
Q
What are the OR rules?
A
- A V 0 = A
- A V 1 = 1
- A V A = A
- A V ¬A = 1
8
Q
Why do we simplify boolean algebra?
A
- practical use in circuit design
- fewer gates = cheaper
9
Q
What is a NAND gate? Truth table?
A
- table in book
- AND combined with a NOT gate
- true all the time unless both inputs are true
10
Q
What is a NOR gate? Truth table?
A
- table in book
- NOT and OR gate combined
- only true if both inputs are false
11
Q
What is a XOR gate? Truth table?
A
- exclusive OR
- true if one of the inputs is but not if both are
12
Q
What are adder circuits used for?
A
Binary addition - also deals with carry digits
13
Q
What is a half adder?
A
- 2 inputs and a carry digit are fed to it
- carry digit and an output are generated
14
Q
What is a full adder?
A
- 2 inputs and a carry and sent in
- sum of 2 inputs is sent to another adder and combined with original carry digit to create the final sum.
- Carry digit of first sum is sent to a OR gate and combined with carry digit of second sum to produce final carry digit output
15
Q
What is a flip-flop circuit?
A
- circuit compromising of NAND dates (storage used in SSD’s)
- can exist in either on or off state which enables it to store store one item of data (1 or 0). Flips between the 2 states, hence name
- combine to make other range of flip flops
