Systems Architecture Flashcards
What is The different types of cache and what are their purposes?
L1 Cache- Smaller capacity but faster speeds used for frequently to store frequently used data
L2 Cache - Bigger capacity slower speed used to store less frequently used data
What are the main registers in a CPU and what is their purpose
Program counter - holds the address of the next instruction to be executed.
Memory address register - holds the address of the current instruction to be fetched from primary memory or where data should be sent to
Memory data register - holds the contents of the address found in the MAR or the data that is to be transferred to the address in the found in the MAR
Current instruction register - holds the instruction that is currently being decoded and executed
Accumulator - holds the data being processed and the results of processing
What is Clock speed measured in and what does a faster clock speed mean
Clock speed is measured in hertz
Faster clock speed means more instructions completed in a given space of time
How many Fetch Decode Processing Cycles can a 3 MHZ processor do and a 3 GHZ processor
3 Million FDE cycles
3 Billion FDE cycled
What is a processing unit in a CPU called
A core
What is a core capable of and is more cores better
Fetching decoding and executing
instructions. Yes because more cores means 2 instructions can be decoded simultaneously
What does the clock in a CPU do?
It sends regular pulses to synchronize all compoments
What are the key elements in the Von Neumann architecture
Data and instructions both stores as binary digits. they are both stored in the primary memory instructions are fetched one at a time and in order it then decodes and executes it then cycling round to start the cycle
Factors affecting CPU performance
Cache size
clock speed
Number of cores
What 2 things does the Arithmetic Logic Unit do
It performs arithmetic and makes logical operations (decisions) and acts as a gateway between primary memory and secondary storage
What is the purpose of a CPU
to process data and instructions
to control the rest of the system (to some extent)
What is an embedded system and give some examples
A system/small computer that forms a part of a larger system usually has one purpose like a button on a camera or a clock on a digital watch
Explain the Fetch execute decode execute cycle
The PC starts at the address 0 this address is then copied to the memory address register the MAR then sends a signal via address bus to the memory and retrieves it then it sends it to the MAR via the data bus the MAR then copies it to the CIR then the CIR copies it to the control unit then the control unit sends a signal to the PC to increment (increase by 1) then the CU decodes it e.g. Load three this means to load the value in address 3 in the memory. the CU then updates the MAR to address 3 the address bus then gets the data from address 3 and sends it to the MDR it is then copied to the Accumulator
the accumulator temporarily holds this value while the cycle repeats starting from 1. after a second value is decoded then it is sent to the ALU instead of the Accumulator the value in the accumulator is then sent to the ALU and the ALU then does the math and the result is sent to the Accumaltor
What the control Unit does
decodes Instructions.
Co-ordinates FDE cycle by controlling compoments
What is a register
a small amount of high-speed RAM(Random access memory) in the processor
