What is the central processing unit (CPU)?
processor central to all modern computer systems responsible for executing all instructions in a computer
Where is the CPU typically installed?
as an integrated circuit on a single microchip
What are the main components of the CPU?
CU, ALU, registers, buses
what does CU stand for
Control unit
what does ALU stand for
Arithmetic logic unit
what is the control unit
manages the execution of instructions and the flow of data
What is the arithmetic and logic unit
performs arithmetic and logic operations
What is the significance of the von Neumann architecture?
introduced the concept of a stored program computer
main features of the von Neumann architecture
concept of a central processing unit, direct memory access by the CPU, store programs and data in memory
key components of the von Neumann CPU architecture?
CPU, memory, system clock
What operations can the arithmetic and logic unit (ALU) perform?
addition, subtraction, shifting
How are multiplication and division handled by the ALU?
carried out by a sequence of addition, subtraction, and left or right logical shift operations.
What is the role of the Control Unit (CU)?
reads an instruction from memory
Fetch–Decode–Execute cycle
generates control signals
ensures synching of data flow
Where is the address of the instruction stored?
PC
what does PC stand for in the CPU
Program counter
What is the purpose of the system clock?
ensure vital synching of data flow and program instructions
what does the system clock prevent
the computer crashing
what does RAM stand for
random access memory
what is RAM also referred as
Immediate access memory
what is the role of RAM
holds all the data and programs needed by the CPU temporarily
Why is data stored in RAM instead of backing store?
read/write operations using RAM are considerably faster
What are registers in the von Neumann system?
fundamental components that can be general or special purpose.
How are system buses used in a computer?
connect the CPU to the memory and to input/output devices
How is computer memory structured?
made up of partitions
what do partitions consist of
an address and its contents
purpose of the address in the partitions
identifies every location in the memory
how are contents stored in partitions
in binary value
What is the Fetch–Decode–Execute cycle?
Control Unit reads an instruction from memory, decodes it, and then executes it
What is the role of input devices in a computer system?
convert external data into a form the computer can understand and process
What is the role of output devices in a computer system?
show the results of computer processing in a human understandable form
What are system buses in computers?
parallel transmission components used to transmit data
what does each wire in a system bus do
transmits one bit of data.
Name the three common buses used in the von Neumann architecture.
address bus
data bus
control bus
What does the address bus do?
carries addresses throughout the computer system
where is the address bus connected or where does the address bus send addresses
unidirectional between the CPU and memory
what does unidirectional mean
bits travel in one direction only.
Why is the width of the address bus important?
determines the number of memory locations that can be directly addressed at any given time.
What is the function of the data bus?
allowing data to be sent in both directions between the CPU, memory, and input/output devices.
what does bidirectional mean
both directions or two directions
what directional path does the data bus follow
bidirectional
Why is the width of the data bus important?
determines the word length that can be transported
What is a word in computer terms?
a group of bits that can be regarded as a single unit
What is the role of the control bus?
carries signals from the control unit (CU) to all other computer components.
what direction does the control bus
bidirectional
How wide is the control bus typically
8-bits wide
why is the control bus usually 8-bits wide
only needs to carry control signals.
What happens during the Fetch stage of the Fetch–Decode–Execute cycle?
fetched from the memory address stored in the MAR/MDR
copied to the CIR
PC is incremented by 1.
What happens during the Decode stage of the Fetch–Decode–Execute cycle?
fetched instruction is decoded for interpretation and execution
What happens during the Execute stage of the Fetch–Decode–Execute cycle?
CPU passes the decoded instruction
components to carry out the instruction in sequence
What does the system clock do in a CPU?
synching all computer operations
timing signals transmitted
How does clock speed affect CPU performance?
Increasing clock speed increases processing speed
What is overclocking
changing the clock speed higher than designed
how can overclocking be achieved
by accessing the BIOS
what are the potential issues of overclocking
Unsynched operations, overheating, crashing, instability
How does cache memory improve CPU performance?
faster data access times than RAM
what does cache memory store
frequently used instructions and data
where is cache memory located
within the CPU
Why doesn't doubling the number of CPU cores necessarily double performance?
need for communication between the CPU and cores can reduce the potential performance increase.
What components make up one core in a CPU?
made up of an ALU, a control unit, and the registers.
How does the width of the address bus and data bus affect CPU performance?
amount of data that can be transmitted at once
How does increasing bus width affect computer performance?
increases the performance and speed of a computer system.
What is the impact of increasing clock speed on a computer?
potentially increase the speed of a computer
What factors can change a computer’s performance?
altering bus width
altering clock speed
using multi-core CPUs
add cache memories
What is the role of cache memory in a CPU?
speed up a CPU’s performance by storing frequently used instructions
What are instructions in a computer system?
operations decoded in sequence,
made up of an opcode and an operand
What is an opcode?
informs the CPU what operation needs to be done.
What is an operand?
data that needs to be acted on
What is an instruction set?
limited number of opcodes used by the CPU to carry out operations
what does an instruction set form
low-level language instructions understood by the computer
What is the Fetch–Decode–Execute cycle?
sequence of steps used by the CPU to process each instruction in sequence.
What is the X86 instruction set?
standard instruction set used in many modern computers
what manufacturers use X86 instruction set
Intel Pentium
AMD athlon
How are instruction sets different from programming code?
Instruction sets are low-level language instructions
programming code needs interpreters to be converted into instruction sets
Give some examples of instruction set operations.
ADD
JMP
LDA
What does the instruction set operation "ADD" stand for?
adds the values of two operands and stores the result.
What does the instruction set operation "JMP" stand for?
Jump
What does the instruction set operation "LDA" stand for?
Load accumulator
what does the JMP instruction set operation do
jump to a different instruction address in the program, altering the flow of execution.
what does the instruction set operation LDA do
loads a value from memory into the accumulator register
What is an embedded system?
combination of hardware and software designed to carry out a specific set of functions
What is a microcontroller in an embedded system?
a chip that includes a CPU, RAM, ROM, and other peripherals
What is a microprocessor in an embedded system?
integrated circuit with only a CPU on the chip
what does SoC stand for
system on a chip
How can data be inputted into an embedded system?
inputted manually by an operator or automatically via sensors
What is the nature of sensor inputs in embedded systems?
can be analogue or digita
How do non-programmable embedded devices handle software upgrades?
need to be replaced if they require a software upgrade
How can programmable embedded devices be upgraded
can be upgraded by connecting to a computer for software downloads
What are some remote control capabilities of embedded systems connected to the internet?
Embedded systems connected to the internet can be controlled remotely
Why can embedded systems be optimized in their design?
Embedded systems are optimized for specific tasks, allowing engineers to reduce their physical size and cost.
Give an example of the range of applications for embedded systems.
single microcontroller in an MP3 player
Why is a computer not considered an embedded system?
A computer is multi-functional, capable of performing various tasks with different software
What is a system on a chip (SoC) in an embedded system?
microchip that integrates multiple components
includes a microcontroller to manage specific tasks
Use of embedded systems in motor vehicles
engine management
safety features
infotainment systems
Function of embedded systems in set-top boxes
record and playback TV programs
can operate remotely via internet-enabled devices
handle inputs from SSDs and satellite signals
Role of embedded systems in security systems
set security codes in RAM
control outputs like flashing lights, alarms
access remotely
Use of embedded systems in lighting systems
control lights based on time of day
adjust light levels automatically
room occupancy
Importance of embedded systems in office lighting
dimming lights during unoccupied times to save energy
adjust light output based on natural light
Examples of embedded systems in external lighting
fountain light displays
light shows for special occasions
emergency lighting in planes
Use of Bluetooth light bulbs in lighting systems
control each bulb independently
Inputs to embedded systems in vending machines
keypad for item selection
sensors for coin slot