Systems Architecture Flashcards
What does the CPU do?
It fetches and processes instructions
What does FDE stand for?
Fetch Decode Execute
What does CPU stand for?
Central Processing Unit
What are the main components of the CPU?
Control Unit (CU)
Arithmetic Logic Unit (ALU)
Registers
Cache
What are registers?
Small fast memory locations
What does a Program Counter (PC) do?
Holds the address of the next instruction to be fetched
What does a Memory Address Register (MAR) do?
Stores the address of a function being fetched
What does a Memory Data Register (MDR) do?
Stores the data that has been fetched to be stored in memory
What does an Accumulator (ACC) do?
Stores the result of an instruction/ calculation
What does the Control Unit (CU) do?
It controls and co-ordinates all of the activities taken place in the CPU
- Decodes and executes instructions
- Receives signals from the system clock
What does the Arithmetic Logic Unit (ALU) do?
It’s where the arithmetic and logical calculations are done
What is cache?
It temporarily stores frequency used data
Why is cache faster?
It’s closer to the CPU than RAM which provides data and instructions faster
What is clock speed?
It’s the measure of how fast the CPU can process instructions
What is clock speed measured in?
Gigahertz (GHz)
What does 3.5GHz of clock speed mean?
It can perform 3.5 billion FDE cycles per second
What does the higher clock speed mean?
The more FDE cycles are completed per second, this means better performance and more instructions can be processed faster
What is a core?
A complete set of CPU components (able to perform a FDE cycle)
What does more cores mean?
More cores = more instructions can be completed in the same amount of time
Does more cores mean that it will be faster?
Not always as it depends on the software as not all programs can have several instructions processed at once
It also depends on the clockspeed
Do most computers have a big or small cache size?
Cache is quite expensive so small
What is an embedded system?
A computer system built into a device with a dedicated function
What are some examples of embedded systems?
Smart watch, smart fridge, dishwasher, tumble dryer, washing machine, coffee machine
What are the con’s of embedded systems?
Not easy to update
Expensive to create + develop
Needs a lot of testing
Complex systems to design
What are the pro’s of embedded systems?
Small so cheap
Reliable
Low power consumption
Suited for a particular purpose
