Computer Architecture Flashcards
Define main memory
Memory directly accessible by the processor
Define I/O control
Controls flow of information from processor and I/O device
Define Processor
Circuit that execute instruction
Define System Bus
Set of parallel wires that connect independent components of a computer system
Used to pass signals between components
Define Bus width
No of information, in bits, can be transmitted at once on a bus. Corresponds to no of physical lines over which data is sent
Define control bus
Sends control signals to registers, data bus and address bus.
Is bidirectional
Made up of many control lines
Define data bus
Transfers data between processor and memory
Is bidirectional
Define address bus
Is unidirectional
Concerned about passing address one way, from CPU to RAM
Used to identify address of the location
Von Neumann VS Harvard architecture
Von Neumann:
Competition for resources as all share same bus
Cheaper (marginally)
Development of CU is cheaper and faster
Error in program, rewrite instructions + crash program execution
Often used in RAM/ROM
Harvard:
Instructions + r/w data take place in parallels so faster
Avoids bottleneck occurring
Instructions and data memory have different word lengths
Avoids data being executed as code (method used by hackers)
Free data memory cannot be used for instructions, vice versa
Often used in cache, embedded systems, Digital signal processors
What are the modern CPU design principles
All instructions are executed by hardware
Rate at which executed is maximised
Instructions are easy to decode
Only load and store instructions reference main memory
Abundance of registers to be available
What can processor performance be defined by
Speed
Scalability
Response time
Power consumption
Etc…
What affects processor speed
Clock speed
Word length
Bus width
Amount of cache memory
Number of Cores
Define:
Clock speed
Word length
Bus width
Cache memory
Multiple Cores
Clock speed: Frequency at which the system clock ticks
Bus width: Number of parallel signal lines or wires
Word length: Number of binary digits in a word
Cache memory: Small amount of fast memory commonly used
Cores: New gen processors use multi cores and parallelism. This allows multiple processors execute more than one process at a time on a separate core
