Logic Gates, Please read before continuing!
NANDLogic gates are known widely known as the universal building block or universal logic gate, this is because you can build every type of logic gate with just this one gate wired in different ways.
The advantages of using the NAND gate is that logic gates come in chips, generally 4 gates to a chip and all containing the same gate. so using NAND gives you these advantages:
1. Less cost
2. Smaller PCB
3. No need to keep as many chips
4. Less soldering
The disadvantage of not using NAND is that you have to many free spaces for example 4 chips each having 4 gates to only use one of each gate in a chip, so using 4 Gates out of a possible 16 this means:
1.Costs are grater than need be
2.Your PCB Layout will be more complicated and large
3.Spend more time than needed designing your PCB
Not to much info on the gates themselves because that's all explained in the link at the top of the post.
NAND Truth table and symbol
The
NAND truth table
A B | Q
0 0 | 1
0 1 | 1
1 0 | 1
1 1 | 0
The six possible gates to make are:
1.
NOT 2.
AND 3.
OR 4.
NOR 5.
XOR or
EXCLUSIVE OR 6.
XNOR or
EXCLUSIVE NOR
NOT
Truth table
A | Q
0 | 1
1 | 0
Simple
NOT gate, inverts the input, made by joining the inputs together
AND
Truth Table
A B
C | Q
0 0
1 | 0
0 1
1 | 0
1 0
1 | 0
1 1
0 | 1
A
NAND and an
NOT linked together, easy.
OR
Truth tables
A B
C D | Q
0 0
1 1 | 0
0 1
1 0 | 1
1 0
0 1 | 1
1 1
0 0 | 1
A
NAND and a
NOT gate joined together like ebony and ivory.
NOR
Truth table
A B
C D E | Q
0 0
1 1 0 | 1
0 1
1 0 1 | 0
1 0
0 1 1 | 0
1 1
0 0 1 | 0
XOR or EXCLUSIVE OR
Truth table
A B
C D E | Q
0 0
1 1 1 | 0
0 1
1 0 0 | 1
1 0
0 1 1 | 1
1 1
0 0 1 | 0
XNOR or EXCLUSIVE NOR
Truth table
A B
C D E F | Q
0 0
1 1 1 0 | 1
0 1
1 1 1 0 | 0
1 0
1 1 1 0 | 0
1 1
0 0 0 1 | 1
Images to come as soon as I can get mahself a Nand chip
