Embedded Systems 1 Syllabus
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Microcontroller Architecture
– Basic CPU and computer system architecture
– Microcontroller vs Microprocessor
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8051 Microcontroller Architecture
– 8051 pin functions
– 8051 register and memory organisation
– 8051 timers, serial port and interrupt operation
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Assembly Language Programming
– Instruction set and addressing modes
– Programming the 8051 peripherals
– Assembler directives
– Development Tools
Embedded Systems 1
1-1
Introduction
Syllabus (cont)
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8051 Interfacing
– Keypads and displays
– Switches and LEDs
– DC and stepper motors
– ADC, DAC
– External memory
– Memory mapped I/O
– I/O Port Expansion
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Address decoding
Embedded Systems 1
1-2
Introduction
Assessment
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Exam 60%
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CA 40%
– Weekly lab work
– Lab exams
– Mini-project
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Note
– Both the exam and CA work are fail elements
– i.e. if you fail a fail element you fail the module
– Fail element pass mark is 30%
Embedded Systems 1
1-3
Introduction
Recommended Reading
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8051 Handouts from class
The 8051 microcontroller : architecture, programming and applications, Kenneth J.
Ayala, West Publishing
The 8051 cookbook for Assembly and C, S. Yeralan, Rigel Press
The 8051 family of microcontrollers, Richard H. Barnett, Prentice Hall
The 8051 microcontroller, I. Scott MacKenzie , Prentice Hall
Useful Websites
• www.gmitweb.gmit.ie/electronics/nokeeffe – module web page
– Contains lectures, lab material, tutorials and reference material
• www.8052.com - good 8051 tutorial
• www.keil.com - 8051 development tools (free evaluation version)
Embedded Systems 1
1-4
Introduction
Computer Architecture
Parallel
I/O
CPU
Program
Memory
Data
Memory
Serial
I/O
I/O
Interface
Data Bus
Address Bus
Control Bus
Embedded Systems 1
1-5
Introduction
Computer Architecture
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CPU
– Control unit
– ALU (Arithmetic and Logic Unit)
– Registers
Program Memory
– Stores application code and constants
Data Memory
– Stores variables used by application
Input/Output (I/O) Interface
– Interface to external peripherals
– Serial peripherals e.g. GSM MODEM, GPS receiver
– Parallel peripherals e.g. ADC, DAC, Displays
Embedded Systems 1
1-6
Introduction
Microprocessor vs Microcontroller
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Microprocessor
– Main purpose - data processing
– CPU , clock circuit, interrupt circuit, registers + Cache
– Additional components - (peripherals) needed e.g. memory, I/O, timers etc
– Very fast clock (high MIPS) – up to 3.4GHz
– Large word size (typically 32 or 64 bit)
– High-end applications
• PC’s, Workstations
• Mobile Phones
Microcontroller
– Single chip solution - Incorporates peripherals: eg: ROM, RAM, timers, parallel
& serial I/O.
– Most instructions deal with movement of data within the microcontroller.
– Slower clock - max 50MHz
– Smaller word size – typically 8 or 16 bit (up to 32 bit)
– Lower cost than microprocessors
– A system can be built using few external IC’s
Embedded Systems 1
1-7
Introduction
Microprocessor (CPU) Architecture
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Most instructions involve movement of data external to the microprocessor chip
– Control unit controls movement of data into, out of and around the
microprocessor
– ALU executes all arithmetic and logic instructions
– CPU contains a limited number of registers and memory
To build a computer system additional components must be added
Accumulator
Control Unit
Cache
Memory
PC
ALU
Embedded Systems 1
Working
Registers
1-8
Interrupt Circuit
Clock Circuit
Introduction
Microcontroller Architecture
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Most instructions involve movement of data within the microcontroller chip
Small microprocessor
Power
ROM
RAM
CPU
Clock
I/O Ports
General
Purpose
Registers
I/O Pins
e.g. LEDs, Switches,
Keypad, Display
Timers
Data/Address/Control Bus
Embedded Systems 1
1-9
Introduction
Microcontroller Applications
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Consumer Electronics
– Cordless phones
– Televisions
– CD players
Automobile
– Fuel injection
– ABS
Computers
– Keyboard
– Mouse
– Disk controller
House
– Washing machine
– Microwave
Embedded Systems 1
1-10
Introduction
Microcontroller Application Example
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Washing Machine
– Switch inputs to select cycle, turn machine on/off
– Output to control spin speed of drum
– Outputs to open close water input/output valves
– Outputs to turn on/off water heating elements
– Outputs for LED status information
– Timers control spin duration, motor speed control
Motor
Valves
Cycle
Selection
Switches
µController
Heating
Elements
LEDs
Embedded Systems 1
1-11
Introduction
Microcontroller Projects
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Degree Level
– Real time bus timetable
– Golf ball positioning system using GPS
– 2-dimensional plotter using a remote controlled vehicle
– Remote house alarm system
– Voice controlled vehicle
Embedded Systems 1
1-12
Introduction
Review of Numbering Systems
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Binary (base 2)
– Digits 0 and 1
– Binary number 1010 = (1 x 23) + (0 x 22) + (1 x 21) + (0 x 20)
= 10 decimal
Hexadecimal (base 16)
– A single hexadecimal digit can represent a 4-bit binary number
(0000 to 1111)
– Hex digits 0 to 9 and A to F represent the decimal numbers 0 to 15
– 5A Hex = 01011010 binary = (5 x 161) + (10 x 160) = 90 decimal
– In C programming a Hex number has the prefix “0x”
BCD (Binary Coded Decimal)
– BCD uses a 4-bit binary code to represent a number in the range 0 to 9 decimal
(0000 to 1001)
– 19 decimal = 00011001 BCD = 00010011 Binary = 13 Hex
Embedded Systems 1
1-13
Introduction
Number Systems
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Complete the following table: Decimal
Binary
Hex
BCD
13
00001011
0x0D
00010011
21
00111111
0x7D
10000011
Embedded Systems 1
1-14
Introduction