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computing unit 1 revision, additional terms, CPU parts - Coggle Diagram
computing unit 1 revision
embedded systems-
an embedded system is a small computer that forms part of
a larger system,device or machine. It included software and hardware.
examples : ATM, WASHING MACHINE, MICROWAVE
factors affecting CPU performance
if the cpu has a slow clock speed it will perform slower cycles slower
if a cpu has multiple cores it can do more than one program at once simultaneously but sometimes it can be slower with more cores as some programs don't have threading and use older code
if the cache is too big it can spend too long finding the instruction . If its too small it may take a while to load the
instruction
the cpu
the cpu's function is to fetch instructions. decode them and then execute them .They control the computer system
FDE CYCLE:
Decode- instructions in MDR are decoded by the C.U
Excecute- the instruction is executed by the A.L.U and the result is stored in the Accumolator
Fetch- the value of the Program counter is copied to the MAR and the address is used to find the instruction in the M.M. Instructions stored in the MDR. PC is incremented by 1
all the CPU structures and key definitions
Control Unit- directs operations within the computers processor
Arithmetic Logic Unit- does all the arithmetic and logic operations
Accumulator - stores intermediate results during calculations
Current instruction Register- holds what is being decoded right now allowing it to be decoded step by step
Memory Data Register- temporarily holds data about to be written into computers memory
clock speed- the number of cycles a processor can carry out each second (hz)
Memory Address Register- stores the memory address of data or instructions that need to be fetched from the memory
threading- to do more than one task at once
Program counter- keeps track of the address of the next instruction to be fetched and executed in a computer program
incremented - increase
data types
syntax- coding rules/logic
string- collection of letters, numbers or symbols
loop- something that repeats
integer-whole number
variable- something that changes an outcome
selection- allows a program to test several conditions and execute based on which one is true
boolean- true or false
float- decimal
function- A block of statements that returns a specific task
cache- stores instructions that are to be executed immediately
additional terms
CPU parts