A Programmable Logic Device

1
A Programmable Logic Device

• Module M1.3
• Section 3.3

2
A Programmable Logic Device

• Multiple-input Gates
• A 2-Input, 1-Output PLD

3
Multiple-input Gates
Z
Z
2
1
Z
Z
4
3
4
Multiple-input AND Gate
Z
1
Output is HIGH only if all inputs are HIGH
Z
1
An open input will float HIGH
5
Multiple-input OR Gate
Z
2
Output is LOW only if all inputs are LOW
Z
2
6
Multiple-input NAND Gate
Z
3
Output is LOW only if all inputs are HIGH
Z
3
7
Multiple-input NOR Gate
Z
4
Output is HIGH only if all inputs are LOW
Z
4
8
A Programmable Logic Device
9
A Programmable Logic Device
A X !X Y !Y 0 0 0
10
A Programmable Logic Device
A X !X Y !Y 0 0 0
Z A B 0 B B
11
A PLD AND Gate
12
A PLD OR Gate
13
Sum of Products Design
Design an XOR gate
X Y Z 0 0 0 0 1 1 1 0 1 1 1 0
m1 !X Y m2 X !Y
Z m1 m2 (!X Y) (X !Y)
14
A PLD XOR Gate
15
What type of gate is this?
X
Y
removable
jumpers
A
1
Z
2
B
X
!X
Y
!Y
16
What type of gate is this?
X
Y
removable
jumpers
A
1
Z
2
B
X
!X
Y
!Y