Download Lecture 5

ECE 101
An Introduction to Information
Technology
Computers
Information Path
Source of
Information
Information
Display
Digital
Sensor
Information
Processor
& Transmitter
Transmission
Medium
Information
Receiver and
Processor
Components in a Simple
Computer (Kuc)
Computer Components
• Memory - contains the instructions and data
– segmented into data units, usually 8-bit bytes,
with each byte having its own address
• Instruction Pointer - maintains the memory
address of the current instruction
• Arithmetic Logic Unit (ALU) - processes
data in the registers according to the
instruction issued by the control unit
Computer Components
• Registers - quickly and easily accessible
memory locations, temporarily store data to
be processed by the ALU
• Flags - 1-bit memories set depending upon
the outcome of the just completed
arithmetic operations
Components in a Simple
Computer (Kuc)
Desktop Computer Hardware
•
•
•
•
Central Processing Unit
Memory
Storage
Input/output
Computer (CPU) Components
CPU - Central Processing Unit
• Manipulates and controls the flow of data
by following the instructions in memory
• Components include control unit, arithmetic
logic unit (ALU), registers, flags and cashe
memory (small fast memory to improve the
CPU’s efficiency
Moore’s Law as it relates to transistor count in Intel microprocessors.
Ref: Turban, Rainer and Potter
Computer Generations (dates approximate)
• 1st-1946-56, vacuum tubes, limited memory
and capacity, very large, heating a concern.
• 2nd-1957-63, transistors, less heat and
cheaper, more stable and reliable.
• 3rd-1964-79, IC (Integrated Circuits) for
storing and processing information.
Introduced software that could be used by
non-technical people.
Computer Generations (dates approximate)
4th-1980-95, VLSI (Very large Scale
Integrated Circuits, hundreds of thousands
of circuits on a chip, ULSI (Ultra-large
scale integration)
Late 4th- 1996-present, GSI (Grand Scale
Integrated Circuit), Over one billion circuits
on a chip
First four generations used Von Neumann
architecture (processing info. sequentially)
5th- Using Massively parallel processing
Memory
• RAM - random access memory (read or
write data) - volatile (memory lost with no
power) MB = 220  1 million bytes
• ROM - read-only memory (reads only
previously stored data) - simpler structure
and greater capacity. Capacity expanded by
DVD-ROM’s with tens of GB’s of data (1
GB = 230  1 billion bytes)
Storage
• Long-term non-volatile retention of data
• Hard disks accommodate large amounts of
data (Giga bytes) but require longer access
times (10 msec) than RAM
• Floppies (now obsolete, 1.44 MB) and ZIP
drives (store 100, 250 MB), also
“writeable” CD-ROM’s (store up to 650
MB and beyond)
• Disk on Key (8 to 512 MB (or more) on
portable key)
Primary Memory Compared to
Secondary Storage Ref: Turban et.al.
Input/Output
• Input
–
–
–
–
Keyboard
Mouse
Scanner
Modem
• Output
– Monitor
– Soundboard
– Printer
Computer Input/Output (Kuc)
I/O Devices
• Digital I/O port or parallel port - up to 16
binary signals that communicate with digital
sensors or controlling devices
• Analog-to-Digital converter (ADC)
• Asynchronous communications port (serial
port) receives and transmits data through a
modem (typically 56bps)
• Network port - connects through a network
interface card (NIC) to high-speed network
(> 1 Mbps)
Software
• Instructions and application programs that
permit computers to accomplish tasks
• As opposed to hardware, software is
flexible and easily modified
• Manipulation of Data
– Arithmetic operations (+-*/, + is fundamental)
– Logic operations (OR, AND, NOT)
– conditional operations (comparative function)
Hierarchy of Software
Software Control of Computers
• Assembly Language
– most basic language (different for each
computer type)
– typically adding registers or moving data into
registers
Software Control of Computers
• Operating System
– set of commands that performs common system
tasks, such as accepting data from the
keyboard, displaying to the monitor, sending
data to the printer
– Intel computers commonly used versions of
Disk-based Operating System written by
Microsoft (MS-DOS)
– Graphical user Interfaces (GUI or “gooey”)
made computers more user friendly
High-Level Programming Lang.
• Instructions are more powerful, more
general, and better suited for programming
a task than the basic assembly language
instructions. Some examples:
–
–
–
–
FORTRAN (FORmula TRANslation)
BASIC
Pascal
C and C+ and C++
Applications Programs
• Common use of spreadsheets and word
processing
• Packages written by a professional
programmer for a specific operating system
Smart Cards
• Uses a computer to store and process data
– Memory card
– Microprocessor card
• Storage on a card without power
– ROM is permanent and fixed
– Solution: EEPROM - Electrically erasable
programmable read-only memory (EEPROM) use of intense ultraviolet light to reset to 0
(loose all charge)
Simple
Smart
Card
(Kuc)
Smart Cards - Memory Type
• First Generation
–
–
–
–
digital memories with 256 bits (32bytes)
information area of 12 bytes for preset info
units area contains the “worth” of the card
all units bits initially 0, spent changes bit to a 1
• Second Generation
– info area of 8 bytes, control area of 3 bytes
– uses 5 “units” counters in base 8
– 8 bits per counter each with equal weight
Memory Organization of a 1st Generation
Smart Card
Memory Organization of a 2nd Generation
Smart Card
Refilling a
Counter
(Kuc)
A set of Counters in a 2nd
Generation memory smart card
containing 10,000 units (Kuc)
Microprocessor Smart Cards
• Advanced smart cards
– Does more than store data
– Can accept money
– complex encryption techniques make money
transactions relatively secure
– can be contact-less using an antenna around the
perimeter of the card
Multiprocessor Computer System
• Efficient Data Base Searches
– Use of many independent computers to
complete a task faster
– Operate in parallel rather than in series;
therefore much quicker
• Serving Multiple Users
– Server ties computers together
• links them together
• provides access to share common resources
Multiprocessor
Computer
Systems