it hardware Flashcards
what are the main sections of the CPU?
the Control unit(CU) and the Arithmetic Logic Unit ( ALU)
what do the ALU and CU contain?
registers
what is the function of the CU?
it controls the execution of each instruction and sends read or write signals to memory and the address of the instruction to be fetched
what is the function of the ALU?
calculations and logical comparisons take place here. Once processed data results may be sent back to memory to be stored there.
what is the accumulator?
it is a register that stores the result of each execution.
what happens when data is stored?
its written from the accumulator to RAM.
what is the function of registers?
they store the current instruction and its data
what are registers made of?
static RAM or (SRAM)
why is SRAM so fast?
they do not contain capacitors. Which have to be constantly refreshed.
How many bits are in CPU registers?
32 or 64 bits
what is the difference between 32 bit processors and 64 bit processors.
32 bit processors have to process information in two stages where as 64 bit processors do so in one stage which improves their performance.
what does paralell processing do?
a method of simultaneously breaking up and running program instructions on multiple multiprocessors.
how does parallel processing work?
Each part is broken into its individual set of instructions and each instruction on a different processor or if a user is running different programs at the same time each program can be run on its own processor
how does hyperthreading work?
by duplicating registers on the chip the next instruction is preloaded into the second set of registers while the first set of registers is being processed reducing the time it took to switch between instructions
what does hyperthreading allow for?
hyperthreading makes it appear as if two sets of instructions are being executed at the same time.
what is a set of instructions called?
A thread
what is the entire program to be processed called?
A process.
what is a process state?
All values related to the process that are stored in the registers.
where is the data of the currently executing instruction saved?
In RAM
where is the state or data of the next process loaded?
from RAM to the registers
how does hyperthreading improve performance?
it allows for fast context switching between two processes eliminating the time of loading and saving into the registers each time there is a switch between processes.
what does a hyperthreaded CPU appear as in the Operating System?
two logical CPU where in actuality there is only one physical CPU with two sets of registers.
what is the important thing to remember about hyperthreading and Operating Systems?
Hyperthreading must be supported by the Operating System.
what is multiprocessing?
It is having multiple CPU called cores on a single CPU chip.