1.1 Systems Architecture Flashcards
What is a computer
A machine that takes data and processes it
What is hardware
The physical components of computer
What is software
The non-physical parts of a computer that tell it how to perform specific tasks
What is an embedded system?
Computers that perform a specific task and are built inside larger systems
What does the CPU do
Fetch, decode and execute instructions
What is the CU and what does it do
Control Unit
Processes data and controls the flow of data
What is the ALU and what does it do
Arithmetic logic unit
Does arithmetic calculations and logical operations
What is the cache and what does it do
Very fast memory, in or near the CPU
Stores frequently used intructions
What is a register
Low-storage, fast to access pieces of memory inside the CPU that holds specific data
What is the PC and what does it do
Program counter
Holds the memory address of the next instruction of each F-D-E
What does the accumulator do
Holds the results of the ALU
What is the MAR and what does it do
Memory Address register
Holds memory addresses about to be accessed
What is the MDR and what does it do
Holds the data/ instructions that have been fetched from primary storage
State the full F-D-E cycle
Fetch:
Memory address transferred from PC to MAR
Instruction is fetched from primary storage
PC increments by 1
Decode:
The instruction is decoded by the CU
Execute:
The instruction is executed by the CPU this could be through the use of calculation by ALU
Examples of embedded systems
SAT-NAV
Washing machine
Dish washer
What is RAM and what does it do
Random Access Memory
Stores instructions currently in use and OS
What does CPU performance depend on
Clock Speed, Cores, Cache
How does Clock speed affect CPU performance
-Clock controls number of F-D-E cycles per second
-‘Overclocking’ a computer increases its clock speed and therefore number of instructions executed per second
How does the number of cores affect CPU performance
Each core in CPU processes instructions separately
The more cores a CPU has the more instructions it can carry out
How does cache size effect the CPU performance
Cache can now store more frequently used instructions
Cache is very fast to access so more instructions are now fast to access meaning increased speed
