1.1 System Architecture Flashcards
What’s the purpose of the CPU
TO manage basic operations of the computer, “the brain”
4 elements to form a basic computer system
1.INput
2. CPU
3.Output
$.Secondary Storage
2 main components of the CPU?
ALU and CU
Most common form of computer architecture
Von Neumann Architecture
What cycle does the CPU continuously do to process instructions
FDE cycle
What is data stored in a computer on?
Binary
Role of the register in the CPU
Hold on to temporary data and instructions being held by the CPU
What is the name of the register which keeps the address of the next instruction to be processed
PC - Programme Counter
Which register is used to store data that is fetched from main memory?
The memory data register (MDR)
Which register is used to tell the CPU where to locate this data?
The memory address register (MAR)
What is the name of the register that temporarily stores the results of logic operations and calculations during processing?
The accumulator (ACC)
What unit of measurement is used to describe the clock speed of a processor?
Hertz/Gigahertz
Suppose a CPU is capable of performing 1 billion operations per second. What is the clock speed of CPU?
1 GHz
Why does increasing the cache size increase the performance of the processor?
The CPU has more immediate access to data, instead of having to fetch the data from RAM, which is slower.
State one drawback of cache memory in comparison with main memory.
Cache memory is much more expensive than main memory.
Typically, around how large is the cache memory located closest to the CPU?
Anywhere between 2 and 64 kB
Does doubling the number of cores exactly double the performance of a processor?
No
What is meant by an ‘embedded’ system?
A computer system which forms part of an electronic device
Give an example of an embedded system that could be found in the human body.
Pacemaker
Give three examples of devices that you can find in your house that may contain an embedded system.
- Fridges 2. Microwaves 3. Digital clocks
Cars are an example of an object with multiple embedded systems for performing different tasks. Suggest two uses for an embedded system in a car.
- Air conditioning 2. Parking sensors
Suggest two reasons why a manufacturer may use embedded systems instead of general purpose computers in their products.
- They are cheaper 2. They can be smaller
How do embedded systems and general-purpose computers differ?
Embedded systems generally perform a single simple task, and don’t have operating systems. General-purpose computer systems can perform multiple tasks and have an operating system.
State two functions of the control unit.
- Sending signals to control the flow of data and instructions 2. Decoding instructions
What is ‘cache memory’? Why is it useful during program execution?
A small section of extremely fast memory used to store commonly used instructions and data. It is useful as the CPU has direct access to the cache.
Order the three levels of cache in order of proximity to the processor (1 = closest, 3 = furthest).
- L1 cache 2. L2 cache 3. L3 cache
Explain the function of the ALU and give some examples of the operations that it carries out.
The ALU carries out mathematical operations / logical operations / shifting operations on data; examples include multiplication, division, logical comparisons.
What is meant by an ‘address’ in the context of a CPU?
A location in the main memory which stores data or instructions
Which bus is used to carry memory addresses from the CPU to main memory?
The address bus
Describe the first process that occurs in the fetch and execute cycle.
(Instructions to be executed are / Data is) fetched from memory.
Suppose data is fetched from main memory. Which register does it get stored in?
The memory data register (MDR)
Suppose an instruction is fetched from main memory. Which register is does it get stored in?
The current instruction register (CIR)
Which register is used to keep track of which memory location to look at for the next instruction?
The program counter (PC)
Which part of the CPU is used to translate instructions into a set of operations that can be performed directly by the CPU?
The control unit
