Unit 4 Flashcards
What’s Von Neumann Architecture?
•Stored Program Concept.
•Storing programs and instructions in main memory.
Types of computational model?
•Sequential: Process an algorithm step by step
•Parallel: One task is processed by several processors
•Multi-Agent: Each task is processed by different autonomous agents(systems) to form a particular function
Requirements for Parallel model?
•An OS that supports multiple processors.
•A software program capable of distributing process between them equally.
How does agent work in Multi-Agent?
-Different Agent works in their own control(Autonomous)
-They cooperate through coordinations and negotiations.
What does process mean?
Performing a series of actions on inputs, accordingly to the given set of rules
What is bus?
A group of connection between devices in a computer (Used to connect CPU,RAM,I/O..)
What’s writing and reading?
•Writing: CPU sends data to memory to be stored at give address
•Reading: CPU retrieve data stored at given address
(both requires the data value and address)
What’s memory address?
A number that uniquely identify a memory location
What’s firmware and it’s function?
Firmware are programs permanently stored in ROM to initialize hardware components or start the OS when switch on.(Small)
Two programs that connects firmware to OS
-BIOS(Basic Input Output System)
-UEFI(Unified Extensible Firmware Interface)
(UEFI replaces BIOS)
Bus on CPU?
-A silver parallel tracks-> bus(wire connecting the chips tgt)
What’s cache memory?
Fast and expensive memory that is used to between CPU and RAM
What makes cache faster?
-Frequently used data is loaded in chunk to Cache from slower RAM.
-Cache is located between RAM and CPU so CPU access at its own speed(Faster)-> Doesn’t need to wait for data from RAM
What’s a bottleneck?
When something is working at full capacity and cannot handle more demands
What’s a cache miss?
-When the requested data for processing is not found in the cache memory
Why was Cache invented?
CPU developed much faster than RAM and
RAM couldn’t keep up with the speed which cause
limited performance by bottleneck.
What happens when Cache miss happen?
-CPU waits for the cache to reload with the correct data
Where is a buffer used?
In I/O devices between themselves and main system as they communicate with different speed
Why is buffer used?
-High speed data transfer between processor and this memory
-So CPU can continue with other tasks while I/O devices takes data from it’s buffer at slower rate.
(Chef CPU prepares dish (data) and serve at buffer and waiter(I/O) Retrieve them
Types of buses and their functions?
Data bus: carries the the value to be read or write to memory.
Address bus: carries the memory address between CPU and memory
Control bus: carries the control signal and clock pulse that determines read or write and when to do.
How does virtual memory work?
•Memory full-> Memory manager swap out least recently used data in RAM to swap area on HDD
•Requested data is swapped in to the free space on RAM
•User can manage amount of area on HDD to use as VM
•More RAM->less need of VM
ALU? CU? Clock?
Arithmetic/Logic Unit: Part of CPU that does calculation and logical operation.
Control Unit: That organises the actions of other parts of CPU.
Clock: Ticks at regular intervals and synchronise the actions of other parts of CPU.