CPU consists of what? (3 marks)
- ALU: Arithmetic and logic units
- Registers and buses
- Control units
What is a microprocessor (1 mark)
An integrated circuit on a chip
What do all of these components do? (6 marks)
PC
MAR
MDR
CIR
ALU
ACC
Program counter: it will increment by 1 to keep track of the next instruction to go through FDE cycle
Memory Address Registers: It will contain the current instructions’s adresses in the RAM
Memory Data Registers: It will contain the actual data of the current instruction from the memory
Current Instruction Register: Hold current instruction’s data to be decoded and executed
Arithmetic and logic units: performs arithmetics calculations and logical calculations
Accumulator: Stores calculations from ALU
What are the 3 types of busses and their directions (6 marks)
Data bus: Bidirectional
Address bus: Unidirectional (CPU -> Memory)
Control bus: Bidirectional
Describe THE FULL PROCESS OF the fetch cycle (4 marks)
- The program counter will be increment by 1 to process the next instruction to go through FDE cycle.
- The memory address register will use the address bus to go to the memory to take the address of the current instructions
- The memory data register will use the data bus to go from the memory to the CPU after has taken the actual data of the current instruction.
- The current instruction register will hold the data of the current instruction to be decoded and excuted.
Factors affecting performance of CPU ( 3 marks)
Cores: each cores will run FDE cycles simultaneously and independently.
Caches: a small memory close to the CPU for faster access
Clock speed: how many instructions are processed in one second
Describe execute cycle (1 mark)
The ALU will do the calculations and ACC will store it
What is an embedded system ( 1 mark)
A computer system that is dedicated for 1 task
How a sensor work? ( 6 marks)
- Sensors will detect analogue data
- The ADC will convert analogue data –> electrical signals for CPU to understand
- Microprocessor compares with its values
- If the value goes out of range, it will convert ana
- If not, then nothing happens :D
Describe 3 types of touchscreen (6 marks)
Capacitive: Made up of 3 layers: conductive metals, glass and protective layer
Resistive: The polyester layer will bend down to contact with the conductive layer
Infrared: lazers are shone across the surface to form a matrix. If it’s interfered, it will know the position.
Advantages and disadvtanges of 3 types of touchscreens ( 6 marks)
Infrared:
+ Unlimited touch life
+ touch with stylus & gloves
- Sensitive to interference like water
Capacitive
+ Multiple touch life
+ High quality
- No gloves or stylus
Resisitve
+ Gloves and stylus
- No resolution & precision
- Prone to damages like scratches.
Examples of optical secondary storage? (3 marks)
Bluray, DVD , CD
Properties of optical, magnetic and solid state
Optical:
+ Uses lazer to create pits and lands for 0 and 1
+ Use read/write hand
+ Has moving parts
Solid state:
+ Use NAND or NOR gates for electron transfer
Magnetic :
+ Uses platters and tracks
+ Use read/write hand
+ Has moving parts
Examples of magnetic secondary storage (3 marks)
HDD,floppy disk, magnetic tape
Examples of solid state secondary storage (4 marks)
SSD, USB, RAM, SD card
What is cloud storage? (3 marks)
Storing data in remote areas
Need internet connection to access
Physical servers are needed to store data
Advantages and disadvantages of cloud storage( 4 marks)
ADS
+ Accessed from anywhere
+ A lot of storage capacity
DISADS:
- Need internet connection
- Expensive
- Risk of losing/leaking data
What is MAC address? (3 marks)
- a unique number that identifies devices on a network
- Static
- First half is the manufacturer ID, second half is the device ID
What is IP address? (3 marks)
- a unique number that identifies devices on a network
- static or dynamic
- public or private
Difference between IPv4 and IPv6 (4 marks)
IPv4:
- 32 bits
- separated by full stops
- range from 0-255
IPv6:
- 128 bits
- 8 groups, each has 4 hexadecimal values
