Vi điểu khiển 8051 chương 1 - Introduction to Microcontrollers

7/31/2019 Vi iu khin 8051 chng 1 - Introduction to Microcontrollers

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H Bch Khoa TP.HCM L Ch Thng-www.tinyurl.com/thongchile

1

The 8051 Microcontroller

L Ch Thng

Ref. I. Scott Mackenzie, The 8051 Microcontroller

Instructor

L Ch Thng

Faculty of Electrical and Electronics Engineering

Ho Chi Minh City University of Technology

(i Hc Bch Khoa TP.HCM)

Email: [email protected]; [email protected]

Website: www.tinyurl.com/thongchile

2L Ch ThngRef. I. Scott Mackenzie


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Objectives

Introduction fundamentals and applications ofmicroprocessors and microcomputers.

Architecture, the instruction set, and applications of8051 microcontroller family

Basic applications of microprocessors, such asinput/output, analog-digital conversion (ADC), and

digital-analog conversion (DAC), and data acquisition.


Grading

Quizzes and homework assignments: 20%

Homework is due at the beginning of class

Mid-term: 30%

Final: 50%



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Textbooks

The 8051 Microcontroller, 2nd Edition, I. ScottMacKenzie, Prentice-Hall, 1995

The 8051 Microcontroller: Architecture, Programming,and Applications, Kenneth J. Ayala, West Publishing

Company


Chapter 1

Introduction to Microcontrollers



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These are

embedded systems

An embedded system is a system in which aprocessor/microcontroller/computer is embedded toperform a specific task or tasks


General-Purpose Microprocessor System

Microprocessors

Integrated ALU and CU

No RAM, ROM, I/O on CPU chip itself

Example: Intels x86, Motorolas 680x0

CPU

General-

Purpose

Micro-

processor

RAM ROM I/O

PortTimer

Serial

Port

Data Bus

Address Bus

Many chips on mothers board

Control Unit(CU)

ArithmeticLogical Unit (ALU)

Central Processing Unit (CPU)



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FIGURE 12 Block diagram of a microcomputer system

Architecture of computers


FIGURE 13 The central processing unit (CPU)

Architecture of CPU

PC-Program counter



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FIGURE 14 Bus activity for an opcode fetch cycle

Opcode fetch, decode, execution


FIGURE 15 Levels of software

Booster loader,BIOS

Utilities

Shell, GUI user- hardware

Keyboard, monitorOther hardwires



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FIGURE 16 Detailed block diagram of a microcomputer system


Integrates CPU, RAM, ROM, I/O ports, on asingle chip

Sometimes called a "computer on a chip"

Typically used in embedded applications

Example: Motorolas 6811, Intels 8051, Zilogs Z8and PIC 16X

RAM ROM

I/O

PortTimer

Serial

COM

Port

Microcontroller

CPU

A single chip

Microcontrollers



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Embedded System

Microcontroller(uC)

sensor

Sensorconditioning

Outputinterfaces

actuator

indicator

sensor

sensor


Positive radix, positional number systems

A number with radix r is represented by a string ofdigits:

An - 1An - 2 A1A0 . A- 1A- 2 A- m + 1A- min which 0 < Ai < r and . is the radix point.

The string of digits represents the power series:

( ) ( )(Number)r = +j = - m

jj

i

i= 0i rArA

(Integer Portion) + (Fraction Portion)

i = n - 1 j = - 1

Representation of Number Systems



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General Decimal Binary

Radix (Base) r 10 2

Digits 0 => r - 1 0 => 9 0 => 1

0

1

2

3

Powers of 4

Radix 5

-1

-2

-3

-4

-5

r0

r1

r2

r3

r4

r5

r -1

r -2

r -3

r -4

r -5

1

10

100

1000

10,000

100,000

0.1

0.01

0.001

0.0001

0.00001

1

2

4

8

16

32

0.5

0.25

0.125

0.0625

0.03125

Representation of Number Systems


400 + 0 + 7 + 0.6 + 0.02 + 0.005 = 407.625

4 0 7 . 6 2 5

102 101 100 . 10-1 10-2 10-3

4x102 0x101 7x100 . 6x10-1 2x10-2 5x10-3

400 0 7 . 0.6 0.02 0.005

Decimal (Radix r = 10)

Binary (Radix r = 2)

1 0 1 . 0 1 1

101.011 B = 4 + 0 + 1 + 0 + 0.25 + 0.125 = 5.375

22 21 20 . 2-1 2-2 2-3

1x22 0x21 1x20 . 0x2-1 1x2-2 1x2-3

4 0 1 . 0 0.25 0.125



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Hexadecimal or Hex (Radix r = 16)

Hexadecimal Decimal Binary Hexadecimal Decimal Binary

0

1

2

3

4

5

6

7

0

1

2

3

4

5

6

7

0000

0001

0010

0011

0100

0101

0110

0111

8

9

A

B

C

D

E

F

8

9

10

11

12

13

14

15

1000

1001

1010

1011

1100

1101

1110

1111

5 A 0 . 4 D 1

5A0.4D1 H = 1280 + 160 + 0 + 0.25 + 0.0508 + 0.0002 = 1440.301

162 161 160 . 16-1 16-2 16-3

5x162 10x161 0x160 . 4x16-1 13x16-2 1x16-3

1280 160 0 . 0.25 0.0508 0.0002


Converting decimal to binary

8 . 625 D = ? B

8 : 2 = 4 remainder 0




0.625 x 2 = 1.25 save the integer digit 1



1 0 0 0 .. 1 0 1 B



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1 4 8 0 . 4 2 9 6 8 7 5 D = ? H

1480 : 16 = 92 remainder 8

92 : 16 = 5 remainder 12




5 C 8 .. 6 E H

Converting decimal to hex


1 1 1 0 1 1 0 1 0 1 1 1 0 1 . 0 1 1 0 1 0 1 B0 0 0

. 6 A H

2 C 9 . E 8 H

0 0 1 0 1 1 0 0 1 0 0 1 . 1 1 1 0 1 0 0 0 B

3 B 5 D .

Converting binary to hex

Converting binary to octal



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BCD (Binary Coded Decimal)

Decimal

0

1

2

3

4

5

6

78

9

BCD(8 4 2 1)

0 0 0 0

0 0 0 1

0 0 1 0

0 0 1 1

0 1 0 0

0 1 0 1

0 1 1 0

0 1 1 11 0 0 0

1 0 0 1

Ex: 12 = 0001 0010 (BCD)

39 = 0011 1001 (BCD)


ASCII Codeb

6b

5b

4

0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1

b3b

2b

1b

0Hex 0 1 2 3 4 5 6 7

0 0 0 0

0 0 0 1

0 0 1 0

0 0 1 1

0 1 0 0

0 1 0 1

0 1 1 0

0 1 1 1

1 0 0 0

1 0 0 1

1 0 1 0

1 0 1 1

1 1 0 0

1 1 0 1

1 1 1 0

1 1 1 1

01

2

34

56

789

AB

CD

EF

NULSOH

STX

ETXEOT

ENQACK

BELBSHT

LFVT

FFCR

SOSI

DLEDC1

DC2

DC3DC4

NAKSYN

ETBCANEM

SUBESC

FSGS

RSUS

SP!

#$

%&

()

*+

,-

./

01

2

34

56

789

:;

?

@A

B

CD

EF

GHI

JK

LM

NO

PQ

R

ST

UV

WXY

Z[

\]

^_

`a

b

cd

ef

ghi

jk

lm

no

pq

r

st

uv

wxy

z{

|}

~DEL



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Boolean (Logical) Operations

a NOT a

0 1

1 0

a b a AND b

0 0 0

0 1 0

1 0 0

1 1 1

a b a OR b

0 0 0

0 1 1

1 0 1

1 1 1

a b a XOR b

0 0 0

0 1 1

1 0 1

1 1 0


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Force a bit or bits to zero

Sometimes called "masking out bits"

Use a "mask" byte with

0's in positions to be cleared (forced to 0)1's in positions to be unchanged

Perform an AND with the mask

x AND 0 = 0 (domination)

x AND 1 = x (identity)

Applying Boolean Operations

L Ch ThngRef. I. Scott Mackenzie


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29

Force a bit or bits to one

Sometimes called "setting bits"

Use a "mask" byte with

1's in positions to be set (forced to 1)

0's in positions to be unchanged

Perform an OR with the mask

x OR 0 = x (identity)x OR 1 = 1 (domination)



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Toggle a bit or bits

Sometimes called "flipping or complementingbits"

Use a "mask" byte with1's in positions to be toggled (complemented)

0's in positions to be unchanged

Perform an XOR with the mask

x XOR 0 = x (identity)

x XOR 1 = NOT x




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Bit patterns from two bytes are to be combined

The important bits of each byte must be aligned with 0 (andunimportant) bits in the other byte

The OR of the two bytes, combines them into one

The bold bits are the important ones:

00110000

OR 00001010

00111010

Combining Bits in Separate Bytes


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Move bits in a byte to the left or right

11011100 shifted left is 10111000

11011100 shifted right is 01101110

In these examples, a zero (0) was brought in tofill the vacated position

Variations on the basic shift fill this positiondifferently

Shifting



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Move bits in a byte to the left or right in acircular pattern

11011100 rotated left is 10111001

11011100 rotated right is 01101110

In these examples, the bit shifted out is used tofill the vacated position

There are some variations of this behavior as well

Rotating


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When a byte (or word) is interpretednumerically (as a binary representation of anumber)

Left shift is equivalent to multiplication by 2Right shift is equivalent to division by 2

5CH shifted left becomes B8H 92 * 2 = 184

5CH shifted right is 2EH 92 / 2 = 46 (remainder if any is thrown away)

Application of Shifts



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Every multiplication can be accomplished byshifting and adding

Just regroup using only multiplications by powersof 2 and additions

10 * n = (8 + 2) * n

= 8 * n + 2 * n

or 10 * n = (2 * (4 + 1)) n

= 2 * (4 * n + n)

Multiplication Tricks


A computer systemcomponent that allows

the storage and retrieval

of data

Main memory is usuallycalled RAM

Memory is usuallyorganized as a table of

bytes or words

0000 3F

0001 2C

0002 41

0003 FF

0004 00

0005 1E

Addressesare usuallyshown in

hexadecimal

Data valuesare usually

bytes

Memory



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RAM: Random Access Memory

Access time does not vary by address

Read & write memory

Typically volatile

ROM: Read Only Memory

Also a random access memory

Retains data even when power is removed

RAM and ROM


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RAM and ROM

RAM ROM



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References

L Ch Thng

I. Scott Mackenzie, The 8051 Microcontroller

Nguyn Trng Lut, Bi ging K Thut S

Cc ti liu trn Internet khng trch dn hoc khng ghi tcgi

Ref. I. Scott Mackenzie

Documents

Vi điểu khiển 8051 chương 1 - Introduction to Microcontrollers