Lecture_1 - Entroduction to MBS

7/24/2019 Lecture_1 - Entroduction to MBS

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BY

SANIRA L ASANTHA

ICBT KANDY CAMPUS

Introduction to Microprocessor

Based SystemsP R I N C I P L E S A N D A P P L I C A T I O N S O F M I C R O C O N T R O L L E R S

L E C T U R E # 1

ACKNOWLEDGEMENT

DR. MALITHA WIJESUNDARA

DEAN ACADEMI C AFFAIRS

S L I I T


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AimsUnderstanding of the applications of microcontroller based systems

Developing skills required to design, write and test software and

interface such systems.


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Learning Outcomes

1. Analyse a system's requirements specification and selectappropriate computer systems and interfaces for subsequentimplementation.

2. Demonstrate a structured, modular, top-down approach tosoftware development in a hardware oriented environment.

3. Design, implement and test systems, written in a high levelprogramming language such as 'C' using appropriateprogrammable interface devices from an initial specificationthrough to validation.


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Learning Outcomes

1. Analyse a system's requirements specification and selectappropriate computer systems and interfaces for subsequentimplementation.

2. Demonstrate a structured, modular, top-down approach tosoftware development in a hardware oriented environment.

3. Design, implement and test systems, written in a high levelprogramming language such as 'C' using appropriateprogrammable interface devices from an initial specificationthrough to validation.


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Delivery & AssessmentTotal Contact Hours :15 Theory sessions 3Hrs x 15 = 45 Hrs.

5 practical sessions -- 3Hrs x 5 = 15 Hrs.

Assessment Criteria

2 Take home assignments

Practical reports

(detailed report should be submitted for each and every practical)


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Text Book(s)Primary TextbookTitle: Quintessential PIC Microcontroller,TheAuthor:Sid Katzen (University of Ulster, United Kingdom)ISBN: 185233942XFormat: Paperback

Release: Date:08/30/2005Pages: 567Publisher: Springer-Verlag New York IncDistributor(s): Springer-Verlag New York Inc


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Text Book(s)Secondary TextbookTitle:

Designing Embedded Systems with PIC Microcontrollers: Principlesand Applications

Author: Tim Wilmshurst (University of Derby, UK)ISBN: 0750667559Format: Paperback

Release: November 27, 2006Pages: 584Publisher: Newnes


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What is an embeddedsystem?An embedded system is a special-purpose computer system designed toperform one or a few dedicated functions, often with real-time computingconstraints.


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Embedded SystemA system whose principal function is not computational, but which iscontrolled by a computer embedded within it.


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Refrigerator example


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Refrigerator example ContIt needs to maintain a moderately stable, lowtemperature within it.

It does this by sensing its internal temperature andcomparing that with the temperature required.

It lowers the temperature by switching on a compressor.


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Microprocessor vsMicrocontroller Microprocessor requires additional circuitry tofunction which are connected via the buses. (Ex: Asoundcard connected to the PCI slot must be used tooutput sound)

Microcontroller - Basic circuitry is built to the unit it selfhence it can function on its own. (Ex: To output sound, amicrocontroller has a DAC is built in.)


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Block diagram of a Computer

e ompu er u sys ems


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e ompu er u sys ems -Memory

The memory unit is necessary for the storage of program instructionsand data.

Memory appears as an array of cells, each holding a bit pattern which

defines the program.

0x45 a=1

0x67 a++

0x23 display a


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Memory ContIn order for the CPU to execute the program stored memory it shouldfetch it.

Hence each memory cell should have a address.

The address of the cell is generated by a decoding network.

0x01 0x45 a=1

0x67 a++

0x23 display a

0x02

0x03

Address Contains


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The Computer Subsystems ALU

& CUALU: The Arithmetic and Logical Unit is where calculations and logicaloperations are performed electronically.

CU: The Control Unit regulates and synchronizes operations of thecomputer. It consists of Programmable Registers and other electronics.The combination of the ALU + the Control Unit is often referred to as theCentral Processing Unit (CPU).


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ALU


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The Computer SubsystemsI/O & Clock generator

Input / Output Units: These units provide the interfaces to the outsideworld. Information enters the computer via the input unit, and results ofthe calculations are directed to the outside world via the output units.

Clock Generator: All operations within the computer are synchronizedto one master clock.


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Bus Architecture

Electronic signals travel through wires, and there aremany connections between various components of thecomputer, particularly between the CPU and the rest.

To minimize the number of connections, the wires ("datapaths") are shared among many devices and signals can

propagate between selected devices and then theselection change.


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Von Neumann ComputerArchitecture


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Von Neumann ComputerArchitecture Cont

In essence, the von Neumann architecture comprises a Central ProcessingUnit (CPU), a memory and a common connecting highway carrying databack and forth.

Both the program and data share the memory of the system.


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Internal Architectureof a Von Neumann computer

ADDRESS BUS

INPUTDEVICE

OUTPUTDEVICE

I/OPORTS

CENTRALPROCESSINGUNIT (CPU)

MEMORY(RAM/ROM)

CONTROLBUS

CONTROLBUS

DATA BUS

Memory

CPU

I/O

Data / Control / Address buses


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Buses Cont

A group of data paths (wires) shared between a numberof devices is known as a "Bus". In a computer, there are

three main groupsAddress bus

Data bus

Control bus


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Address Bus

Address Bus: This group of wires carries the addressinformation. It is unidirectional going from CPU to Memoryor I/O. For Microcontrollers this is typically 16 bits wide,

giving an address range of 65,536 locations.

If the CPU has N address lines, it could address 2N memorylocations.


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Data Bus

This group of wires carries the data information and is bidirectional.

But only one device at a time has its outputs enabled.

Any device connected to the data bus must have threestate outputs.

This allows the device to disable the outputs when notputting data on the bus.


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Control busThis group of wires carries the control and statusinformation. It can be unidirectional or bidirectional. Thewidth of the bus varies with different computers.

Typical control bus signals are, Memory Read, MemoryWrite,

I/O Read, and I/O Write.


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Memory read

To read a byte of data from a memory location, the CPU sends outthe memory address of the desired byte on the address bus.

Next sends out a memory read signal, on the control bus.

Then the data byte form memory travels along the data bus to theCPU

H d C t


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Harvard ComputerArchitecture


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Harvard ComputerArchitecture ContThe Harvard architecture is an adaptation of the standard vonNeumann structure, that separates the shared memory intoentirely separate Program and Data stores.

The diagram shows two physically distinct buses used to carryinformation to the CPU from these disjoint memories.

Each memory has its own Address bus and thus there is nointeraction between a Program cell and a Data cells address. The

two memories are said to lie in separate memory spaces.


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Microcontroller families


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Microcontroller families ContA manufacturer builds a microcontroller family around a fixedmicroprocessor core. Different family members are created by using thesame core, combining with it different combinations of peripherals anddifferent memory sizes.

Each core is added different combinations of peripheral and memorysize, to make a number of family members. Because the core is fixed forall members of one family, the instruction set is fixed and users have littledifficulty in moving from one family member to another.

ll f l f


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Microcontroller families fromdifferent manufacturers

Manufacturer Microcontroller family

Atmel AT91SAM7, AT91SAM9,

Intel 8048 family , 8051 family, 8096 family

Motorola 68HC05, 68HC08, 68HC11,68HC12

Microchip (PIC) 12FXXX, 16FXXX,18FXXX
http://en.wikipedia.org/wiki/AVR32


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Nokia N97 ARM11

Features:

Resolution: 360x640

OS: Symbian OS v9.4

Color depth: 24bit

ROM: 256MB

RAM: 128MB

Data bearer: HSDPA


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Sony Ericsson P990 Nexperia

PNX4008Features:

Resolution: QVGA (240x320)

OS: Symbian OS

Color depth: 262k

Internal memory: 80MB

Data bearer: UMTS


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LG KC1 - Marvell PXA320Features:

Supports Wireless Broadband

2.8 Touch Screen

QVGA (240*320) with 65k colors

128 MB Ram

512 Rom

OS: Windows Mobile 5.0 PPC PE

Mi t ll d i


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Microcontrollers used inMobiles

Mobile Microcontroller

Nokia N97 ARM11

Sony Ericsson P990 Nexperia PNX4008

LG KC1 Marvell PXA320


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Processor features

Microcontroller Bits Speed Instruction set Features

ARM11 64-bit 532-665MHz

RISC Power Management 4 cores Enhanced for video

processing

NexperiaPNX4008

32-bit 208 MHz RISC 2D/3D GraphicsAccelerator Integrated DSP

Marvell PXA320 32-bit Up to820MHz RISC Power ManagementSupported

Hardware videoacceleration.

Design challenges and considerations


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Design challenges and considerationsin Embedded Systems

Limited memory

Limited processing power

Reduced power consumption by disabling unwanted peripherals

and activating peripherals when requiredLow cost

Less weight / Smaller Size

Security

Reliability

Documents

Lecture_1 - Entroduction to MBS