1.1 Flashcards
1
Q
What takes place during the fetch-execute cycle? (7)
A
- Instruction fetched from memory
- Instruction decoded
- Executed
- Process is repeated
- PC is incremented
- Instruction transferred to MDR
- Address of instruction to be fetched in MAR
2
Q
What is clock speed?
A
- The number of FDE cycles executed per second
- Measured in Hz
- Faster = more instructions can be executed
3
Q
What is cache?
A
- Small amount of very fast memory that temporarily stores recently used instructions
- Level 1 is the fastest but it has the smallest capacity
4
Q
What are cores?
A
- A complete copy of CPU (processing unit)
- More cores = more tasks can be executed at once (but requires communications and some softwares are not designed to make use of multicores therefore does not equal to double speed)
5
Q
What are the factors affecting the speed of the CPU?
A
- Clock speed
- Number of cores
- Cache size
- RAM size
6
Q
What is the control unit?
A
- Coordinates all of the CPU’s actions in the FDE cycle
7
Q
What is the arithmetic logic unit?
A
- Performs mathematical calculations
- Makes logical comparisons
8
Q
What are registers?
A
- Tiny and super fast memory holding a single instruction/address
9
Q
What are the four registers?
A
- Accumulator
- Memory Address Register
- Memory Data Register
- Program Counter
10
Q
What is the accumulator?
A
- Holds results of calculations performed by the ALU
11
Q
What is the memory address register?
A
- Stores the address of current instruction/data to be fetched from or stored in memory
12
Q
What is the memory data register?
A
- Stores the data which has been fetched from or is to be written to memory
13
Q
What is the program counter?
A
- Stores address of next instructions to be run
- Once instruction is fetched, value is incremented by one
14
Q
What is an embedded system?
A
- Has limited functions
- Built into a larger machine
- Cannot be modified once manufactured
- Program controlling them is stored in ROM
15
Q
Give some examples of an embedded system
A
- Washing machine
- Smart watch
- Air conditioning
- Alarm clocks
16
Q
What are the benefits of embedded systems?
A
- Highly efficient as firmware has very close control over the hardware
- Easy to design because less components are required
- Cheap to produce
- Low in power consumption due to limited tasks to be executed
- Compact in size
17
Q
State the purpose of the CPU
A
- To process instructions requested by the user
- To fetch and execute them
18
Q
Explain why something is a computer system
A
- An electronic device that takes input, processes data and delivers output
19
Q
What is the name of the computer architecture that is the basis of most digital computer systems?
A
- Von Neumann architecture
20
Q
What is the FDE cycle?
A
- Fetch decode execute
- Complete process of retrieving an instruction, decoding it and carrying it out
