c11 Flashcards
Define control unit
Controls the FDE cycle by sending control signals to parts of the CPU. Sends and receives signals to peripheral components through control bus
Define the clock
Send pulses to other components to coordinate activities.
contains vibrating quartz crystals. measured in hz/ghz
Define Registers
Memory locations within the CPU faster than RAM. Used to store the most frequently needed data. Some are reserved for specific functions
Define the cache
Internal memory, faster than RAM. The smaller the cache level the faster data retrieval date is.
define accumalator.
A register that stores data while a sum is being done.
Define Program Counter
Stores the address of the next instruction
Define MAR
Memory address register. Stores the address of the current instruction that is to be fetched from RAM
define MDR
Memory data register. Receives and stores the next program instruction/data
Define the FDE cycle
FETCH: CPU sends memory address to RAM through address bus of the next instruction. RAM sends the data to the CPU via the data bus. DECODE: Decodes the instruction from the RAM and decides what to do. EXECUTE: CU sends signal to components to execute.
Define ALU
Arithmetic and logic unit. Carries out arithmetic and logic operations.
Define RAM
Memory used by the computer to store while it is running.
Adv + disadv of RAM
ADV: Faster data retrieval then secondary storage.
DISADV: volatile - data is lost when computer is turned off. can only be used when the computer is turned on.
Order of speed of data retrieval. Slow to fast
secondary storage - RAM - Cache - Registers
What can be modified to affect CPU performance
Clock Speed
Cache size
No. cores
define increasing clock speed
increasing the number of instructions per second. Will need to dissipate heat more. - water/liquid nitrogen cooling.
Increasing cache speed
The smaller the cache, the faster data retrieval is. Increasing number of levels speeds retrieval
Increasing Number of cores
Will speed up a program only if it is designed to run on multiple cores
Parallel processing
Multiple cores working on one program
Multitasking
Multiple cores working on multiple programs
Threading
One core performing 2 instructions at once. (virtual cores)
What is an embedded system
A computer embedded within a larger device. Usually a single PCB. designed to perform a single task
why are low level languages used to code embedded systems.
-requires less processing power so cheaper.
-less execution time
-Allows greater control of its components
