Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to...
Transcript of Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to...
![Page 1: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/1.jpg)
Chapter 4
Gates and Circuits
![Page 2: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/2.jpg)
Integrated Circuits aka CHIPS
• What’s in this thing????
4–2
![Page 3: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/3.jpg)
4–3
Chapter Goals
• How to make a gate from transistors
• How to make integrated circuits using
gates
• The basic gates and their behavior
• How gates are combined into (useful)
circuits
![Page 4: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/4.jpg)
4–4
Chapter Goals
• Describe gates and circuits using:
– Boolean expressions
– Truth Tables
– Logic Diagrams
• Understand half adders, full adders, and
binary addition circuits
![Page 5: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/5.jpg)
4–5
Computers and Electricity
• TransistorA device that can be used to
make gates
• Gate A device that performs a basic
operation on bit(s)
• Circuits Gates combined to perform more
complicated tasks
![Page 6: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/6.jpg)
4–6
Computers and Electricity
• 3 ways to describe the same thing
– Boolean expressions
– logic diagrams
– truth tables
![Page 7: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/7.jpg)
4–7
Computers and Electricity
• Boolean expressions A mathematical
notation for expressing TRUE/FALSE logic
• Example: F = AB + C
![Page 8: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/8.jpg)
4–8
Computers and Electricity
• Logic diagram A graphical
representation of a circuit
Each type of gate is represented by a specific
graphical symbol
• Truth table A table showing all possible
input value and the associated output
values
![Page 9: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/9.jpg)
4–9
Gates
• Let’s examine the processing of the following
six types of gates
– NOT
– AND
– OR
– XOR
– NAND
– NOR
![Page 10: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/10.jpg)
4–10
NOT Gate
• A NOT gate accepts one input value
and produces one output value
• Aka “an inverter”
Figure 4.1 Various representations of a NOT gate
![Page 11: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/11.jpg)
4–11
AND Gate
• An AND gate accepts two input signals
• If the two input values for an AND gate are
both 1, the output is 1; otherwise, the
output is 0
Figure 4.2 Various representations of an AND gate
![Page 12: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/12.jpg)
4–12
OR Gate
• If the two input values are both 0, the
output value is 0; otherwise, the output is 1
Figure 4.3 Various representations of a OR gate
![Page 13: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/13.jpg)
NAND and NOR Gates
• The NAND and NOR gates are essentially the
opposite of the AND and OR gates, respectively
Figure 4.5 Various representations of a NAND gate
Figure 4.6 Various representations of a NOR gate
4–15
![Page 14: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/14.jpg)
4–14
Constructing Gates
• Transistor A device that acts as a switch, either
open or closed (on or off)
– A transistor has no moving parts, yet acts like
a switch
– It is made of a semiconductor material, which is
neither a particularly good conductor of electricity,
such as copper, nor a particularly good insulator, such as rubber
![Page 15: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/15.jpg)
4–15
Constructing Gates
• Transistor terminals
– Source
– Base
– Emitter
• If the electrical signal is
grounded, it is allowed to
flow through an alternative
route to the ground (literally) where it can do no harm
Figure 4.8 The connections of a transistor
![Page 16: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/16.jpg)
4–16
Constructing Gates
• It turns out that, because the way a transistor
works, the easiest gates to create are the NOT,
NAND, and NOR gates
Figure 4.9 Constructing gates using transistors
![Page 17: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/17.jpg)
4–17
Combinational Circuits
• Consider the following Boolean expression A(B + C)
Page 100
Page 101
![Page 18: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/18.jpg)
4–18
Adders
• At the digital logic level, addition is
performed in binary
• Addition operations are carried out
by special circuits called, appropriately,
adders
![Page 19: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/19.jpg)
4–19
A Half Adder
• Recall that 1 PLUS 1 = 10 in base two
• In other words: 0 with a carry of 1
Inputs Outputs
A B Carry Sum
0 0 0 0
0 1 0 1
1 0 0 1
1 1 1 0
![Page 20: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/20.jpg)
4–20
Half Adder Circuit
• Two Boolean
expressions:
sum = A ⊕ B
carry = AB
Page 103
![Page 21: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/21.jpg)
A Full Adder
• A circuit called a full adder takes the
carry-in value into account
Inputs Outputs
A B Carry In
Carry-
Out Sum
0 0 0 0 0
0 0 1 0 1
0 1 0 0 1
0 1 1 1 0
1 0 0 0 1
1 0 1 1 0
1 1 0 1 0
1 1 1 1 1
![Page 22: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/22.jpg)
Integrated Circuits
• We can combine 4 full adders to make a
Four-bit Adder Circuit (about 60
transistors)
![Page 23: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/23.jpg)
Integrated Circuits aka CHIPS
• What’s in this thing????Chip Fabrication Technology
4–23
![Page 24: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/24.jpg)
4–24
Integrated Circuits
• Integrated circuit (also called a chip) A
piece of silicon on which many gates have
been embedded
![Page 25: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/25.jpg)
“Silicon Valley”
• Sand is mostly Silicon Dioxide
4–25
![Page 26: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/26.jpg)
“Silicon Valley”
• Silicon Dioxide ingots and wafers
4–26
![Page 27: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/27.jpg)
“Silicon Valley”
• Photolithography “Printed” with lots of
copies of some circuit
4–27
![Page 28: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/28.jpg)
Integrated Circuits aka CHIPS
• What’s in this thing????Computer Architecture: Combining Abstractions into larger
Abstractions
4–28
![Page 29: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/29.jpg)
Transistors and Gates
4–29
![Page 30: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/30.jpg)
4–30
Integrated Circuits
An simple chip containing 4 independent
NAND gates (about 8 transistors)
![Page 31: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/31.jpg)
Integrated Circuits
• A four-bit Full Adder Circuit
![Page 32: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/32.jpg)
Integrated Circuits
• An Arithmetic Logic Unit (ALU) has
adders and other things in it
![Page 33: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/33.jpg)
Integrated Circuits
• A simple Central
Processing Unit, or
CPU has an ALU
and other things
• Take Engineering
303 Digital Logic
Design!!
![Page 34: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/34.jpg)
4–34
CPU Chips
• A recent CPU chip (Intel Nehelem) 731
Million transistors
![Page 35: Chapter 4libvolume3.xyz/computers/btech/semester8/vlsidesignand... · 2014-12-28 · • How to make a gate from transistors • How to make integrated circuits using gates • The](https://reader033.fdocuments.us/reader033/viewer/2022041901/5e609410a78e5f558225ce1f/html5/thumbnails/35.jpg)
The Future of the IC
• Global Competition
• Further Integration (ARM)
4–35