This document discusses an embedded systems presentation submitted by Amandeep Singh. It provides definitions and examples of embedded systems, noting they are designed for specific applications like industrial machines, medical equipment, and toys. It also summarizes key aspects of embedded system components like microcontrollers, addressing modes, and applications. Recent examples highlighted are devices that aid communication for the deaf, integrate weighing and dimension measuring, and allow adjustable cushioning in smart shoes.

1. SUBMITTED TO PRESENTED BY
Mr. ABHISHEK SHARMA AMANDEEP SINGH
100640418009
ECE-A

2. Embedded System Introduction
“An embedded system is some combination of computer
hardware and software, with either fixed or programmable
capabilities, that is specifically designed for a particular kind of
application device”
Embedded systems are very specific, and built to handle a
particular task.
Industrial machines, automobiles, airplanes, trains, medical
equipment, video cameras, phones, PDAs, home appliances,
vending machines, and toys are among the many possible hosts
of an embedded system.

3. Embedded Systems Are Found in..
 Personal information products: Cell Phone, Digital watches,
Pocket recorder, Calculator.
 Computer components: Mouse, Keyboard, Modem, Sound
card.
 Home appliances: Door locks, Alarm clock, Thermostat, Air
conditioner, TV remote, VCR, Refrigerator, Exercise
equipment, Washer/dryer, Microwave oven.
 Industrial equipment: Temperature/pressure controllers,
Counters, Timers, RPM Controllers.
 Toys: Video games, Consoles, Remote controlled cars.

4. Why do we need to learn about
Embedded Systems?
 Embedded Systems has witnessed tremendous growth in the last one
decade.
 Nowadays nearly all the communication, digital entertainment,
portable devices, are controlled by them.
 Conventionally chip manufacturers laid emphasis on developing
faster processors to meet the ever increasing performance
requirements, but now have started manufacturing compact devices,
while efficiently managing power consumption and also improving
their performance.
 Greater value to mobility is one of the prominent reasons for the rise
and development of Embedded Technologies.

5. Microcontrollers
 Are designed to do some specific task.
 On-chip memory and ram, rom, I/O ports, timers, and other
peripherals.
 Used in applications where, the space circuit takes, the
power it consumes, and the price per unit are much more
critical considerations than the computing power.
 Example ： Intel’s 8051, PIC 16C72, Motorola 68000
CPU RAM ROM
A single chip
Serial
I/O Timer COM Microcontroller
Port Port

6. Microcontroller Architectures
Memory
0
Address Bus
Program
CPU Data Bus + Data Von Neumann
2n
Architecture
Memory
0
Address Bus
Program
CPU Fetch Bus Harvard
Address Bus 0 Architecture
Data Bus Data

7. Overview of 8051 family
8051 is a 8-bit microcontroller, first introduced by Intel corporation in 1981
8051 is the original member of the 8051 family.
Other members of 8051 family
8052 and 8031 are the other family members of 8051. The following
table gives comparison of 8051 family members.
Feature 8051 8052 8031
ROM(on-chip program space in bytes) 4K 8K 0K
RAM(bytes) 128 256 128
Timers 2 3 2
1/O pins 32 32 32
Serial Port 1 1 1
Interrupt sources 6 8 6

8. Features of 8051
 8-Bit CPU optimized for control
applications
 128 bytes RAM
 4K bytes ROM
 Four bi-directional I/O ports
 UART (serial port)
 Two 16-bit counters/timers
 8-bit data bus-It can access 8 bits of
data in one operation
 16-bit address bus-It can access 216
memory locations of RAM and ROM

9. 8051 PIN DESCRIPTION
P1.0 1 40 Vcc
P1.1 2
39 P0.0 (AD0)
P1.2 3 P0.1 (AD1)
38
P1.3 4 37 P0.2 (AD2)
P1.4 5 36 P0.3 (AD3)
P1.5 6
35 P0.4 (AD4)
P1.6 7 34 P0.5 (AD5)
P1.7 8 8051 33 P0.6 (AD6)
RST 9
32 P0.7 (AD7)
(RXD) P3.0 10 31 EA/VPP
(TXD) P3.1 11
30 ALE/PROG
(INT0) P3.2 12 29 PSEN
(INT1) P3.3 13 28 P2.7 (A15)
(T0) P3.4 14 27 P2.6 (A14)
(T1) P3.5 15 26 P2.5 (A13)
(WR) P3.6 16 25 P2.4 (A12)
(RD) P3.7 17 24 P2.3 (A11)
XTAL2 18 23 P2.2 (A10)
XTAL1 19 22 P2.1 (A9)
GND 20 21 P2.0 (A8)

10. I/0 Ports
8051 microcontroller has 4 I/O ports P0, P1, P2 and P3 each use 8 pins,
making them 8 bit ports. All the ports upon RESET are configured as input,
ready to be used as input ports. When first 0 is written to a port, it becomes
output port. To reconfigure it as input, a 1 must be sent to the port.
Port 0: Port 0 occupies a total of 8 pins (pins 32-39).It can be used for input
or output. To use the pins of port 0 as both input and output ports, each pin
must be connected externally to a 10K ohm pull-up resistor.
Port 1: Port 1 occupies a total of 8 pins (pins 1- 8). It can be used as input or
output. This port does not need any pull-up resistors since it already has pull-
up resistors internally.
Port 2 : Port 2 occupies a total of 8 pins (pins 21- 28). It can be used as input
or output. Just like P1, P2 does not need any pull-up resistors.
Port 3 : Port 3 occupies a total of 8 pins (pins 10 -17). It can be used as input
or output. P3 does not need any pull-up resistors. Port 3 has the additional
function of providing some extremely important signals such as interrupts,
timers, etc.

11. Port 3 Pins
Pin number Description
RXD (Pin 10) Used for receiving data serially
TXD (Pin 11) Used for transmitting data serially
INT0 (Pin12) External interrupt 0
INT1 (Pin13) External interrupt 1
T0 (Pin14) and Timer/counter 0
T1 (Pin15) Timer/counter 1
WR (Pin 16) Write to external memory
RD (Pin 17) Read from external memory

12. Pin number Description
Vcc (Pin 40) Provides supply voltage to the chip.
GND (Pin 20) It is the Ground.
XTAL1 (Pin19) and The 8051 has an on-chip oscillator but requires an external clock
XTAL2 (Pin18) to run it. Most often quartz crystal oscillator is connected to
inputs XTAL1(Pin 19) and XTAL2(Pin 18).
RST (Pin 9) It is the input pin. Upon applying high pulse to this pin the
microcontroller will reset and terminate all activities.
EA /VPP(Pin 31) Enable Access pin. EA should be connected to Vcc to indicate
that the program code is stored in microcontroller's on-chip
ROM. To indicate that the program is stored in external ROM this
pin is connected to Ground.
PSEN (Pin 29) PSEN stands for “Program store enable” This signal is mainly
used for fetching instructions from external code memory.
ALE/PROG (Pin 30) ALE(address latch enable) is an output pin and is used for both
data and address transmission.

13. Timers/Counters
Microcontroller 8051 has two timers/counters:-
Timer T0
Timer T1
Each are of 16 bits, so can counts 216 = 65536
Both these registers can be configured to operate either
as timers or event counters.
Each counter may be programmed to count internal clock
pulses acting as a timer and if programmed to count
external clock pulses then it is called counter.

14. 8051 Interrupts
“An interrupt is an external or internal event that disturbs
the microcontroller to inform it that a device needs its
service”
A Microcontroller can serve various devices. There are two
ways to do that:
 Interrupts
 Polling
The program which is associated with the interrupt is called
the interrupt service routine (ISR) or interrupt handler.

15. Interrupt Vs Polling
1) Interrupts
 Whenever any device needs its service, the device notifies the
microcontroller by sending it an interrupt signal.
 Upon receiving an interrupt signal, the microcontroller
interrupts whatever it is doing and serves the device.
 The program which is associated with the interrupt is called the
interrupt service routine (ISR) or interrupt handler.
1) Polling
 The microcontroller continuously monitors the status of a given
device.
 When the conditions met, it performs the service.
 After that, it moves on to monitor the next device until every
one is serviced.

16. RAM Allocation in 8051 Scratch Pad
There are 128 bytes of RAM in the 8051
assigned addresses from 00 to 7FH
Bit-Addressable RAM
The 128 bytes are divided into 3 different
groups as follows:-
 A total of 32 bytes from locations 00 to Register Bank 3
1F hex are set aside for 4 register
banks.
Register Bank 2
 A total of 16 bytes from locations 20H
to 2FH are set aside for Bit- Register Bank 1
Addressable RAM.
 A total of 80 bytes from locations 30H Register Bank 0
to 7FH are used for read and write
storage, called scratch pad.

17. 8051 Addressing Modes
The CPU can access data in various ways, which are
called addressing modes.
Different addressing modes are:
 Immediate Addressing
 Direct Addressing
 Register Addressing
 Register Indirect Addressing

18. Immediate Addressing
 Used to Load information into a register.
 Source operand is constant.
 The immediate data must be preceded by “#”
Example MOV A, #10H ; Loads 10H to A
MOV R4, #10 ; Loads the decimal value 10 to R4
MOV DPTR, #1000H ; DPTR=1000H
Direct Addressing
 Value to be stored in memory is obtained by directly retrieving it
from another memory location.
 All 128 bytes of RAM can be accessed, but it is mainly used for
accessing memory locations 30-7FH.
Example MOV A,30H ; Copy data from address 30H into Accumulator.

19. Register Addressing
Involves the use of registers to hold the data to be manipulated.
The source and destination registers must match in size.
MOV DPTR, A will give an error
The movement of data between Rn registers is not allowed.
MOV R4, R7 is invalid
Example MOV A, R0 ; Copy the contents of R0 into A
MOV R4, A ; Copy the contents of A into R4
ADD A, R7 ; Adds contents of R7 to the contents of A
Register Indirect Addressing
An address is considered to be the address of an address, rather than the
address of a value.
Only registers R0 and R1 are used for this purpose
Example MOV A, @R1 ; The value inside R1 is considered as an address,
which holds the data to be transferred to accumulator.

20. Applications Of Microcontrollers
 Energy Management: Efficient metering systems help in controlling energy
usage in homes and industrial applications. These metering systems are made
capable by incorporating microcontrollers.
 Touch screens: Large number of microcontroller providers incorporate touch-
sensing capabilities in their designs. Portable electronics such as cell phones,
media players and gaming devices are examples of microcontroller-based touch
screens.
 Automobiles: 8051 finds wide acceptance in providing automobile solutions.
They are widely used in hybrid vehicles to manage engine variants. Additionally,
functions such as cruise control, anti-brake system, fuel management, safety
system have been made more efficient with the use of microcontrollers.
 Medical Devices: Portable medical devices such as blood pressure and glucose
monitors use microcontrollers will to display data, thus providing higher
reliability in providing medical results.

21. Recent Wonders
“Hand Speak”
 Enhance the abilities of deaf
and dumb people.
 M16/62 converts American
Sign Language (ASL)
movements into
alphanumeric characters that
are displayed on lcd.
 Characters can also be
transferred/viewed on PC or
hand-held device PDA.

22. Recent
Wonders
“Weasure”
 A clever system designed
not only to weight, but also
to measure packages of
shipments.
 With a touch of a button
the weight and dimensions
are shown on display and
uploaded to PC through
serial port.

23. Recent
Wonders
“Shoes”
 The microprocessor
embedded in this adidas
running shoe calculates the
pressure between the runner's
foot and the ground five
million times per second and
continuously changes the
cushioning to match an
adjustable comfort level.
 The computer controls a
motor that lengthens and
shortens a cable attached to a
plastic cushioning element. Adidas Salomon AG