1.1 systems architecture Flashcards
(17 cards)
What is the function of the CPU?
To execute the instructions of programs, to process data, and to manage the rest of the hardware.
What is the function of the ALU?
Where all the arithmetic and logical operations of the CPU take place.
What is the function of the CU?
Controls the flow of data within the system and decodes instructions.
What is Cache?
Very fast memory close to the CPU, used to temporarily hold data and instructions that are frequently used or likely to be needed again soon.
Why is Cache faster than RAM?
Because it is closer to the CPU & program. The instruction can be executed much more quickly.
What are Registers? List them
Extremely fast memory locations that are used during the FDE cycle to hold small amounts of data.
Accumulator, program counter, MAR, MDR
What does the Program Counter do?
Holds the address of the next instruction to be fetched from main memory.
What does the Memory Address Register do?
Holds any memory address about to be used by the CPU. The address might point to data or a CPU instruction.
What does the Memory Data Register do?
Holds data or a program instruction temporarily when it is fetched from memory or is to be sent to memory.
What is the Accumulator?
It stores immediate results of calculation from the ALU.
What is the FDE cycle? Describe what happens at each stage
The process by which the CPU processes instructions
Fetch: the instruction is fetched from memory
Decode: the instruction is decoded to figure out what it means
Execute: the instruction is performed
Give the 3 factors affecting CPU performance
Clock speed, number of cores, cache size
How does the number of cores affect CPU performance?
Each core can carry out an independent FDE cycle. So multiple cores can carry out FDE cycles simultaneously (the more cores the faster the CPU can process a batch of data).
How does Cache size affect CPU performance?
A larger cache gives the CPU faster access to more data it needs to process which allows for faster processing.
How does clock speed affect CPU performance?
Clock speed is the number of FDE cycles a CPU can carry out per second (Hz),so the higher the clock speed the quicker the CPU can process data
What are Embedded systems?
Dedicated systems designed to carry out a limited set of functions built into other devices/machines e.g: microwave, washing machine, vending machine.
What are the benefits of Embedded systems?
-Easier to design as they are dedicated to few purposes
-Cheaper to produce
-More reliable & efficient as they only carry out limited function
