system architecture Flashcards
processor
A machine that processes something . The brains of the computer, carry’s out instructions, speed is measured in hertz
MHz
Megahertz measures clock speed, 1 million instructions a second
GHz
Gigahertz a measure of frequency equivalent to one the sand million (one billion) cycles per second
hertz
Number of cycles per seconds
instructions
An action of introducing something
execute
Carry out an instruction
embedded system
A computer within another device
clock speed
The speed the processor carry’s out instructions
cache
Very fast memory between the processor and RAM (random access memory)
core
Part of the processor that executes instructions, dual core can do twice as many instructions where as a quad core can do 4 times
Von Neumann Architecture
Is the computer hardware when program instructions and data are held in the same memory whereas Harvard architecture has separate memory for instructions and another one for data
pc
program counter – holds the address of the next instruction to be fetched
MAR
memory address register – holds the address of the location in the main memory that is to be fetched or written to
MDR
memory data register – holds data fetched from memory or about to be written to memory
CIR
current instruction register – holds the instruction that has been fetched from memory and is decoded and instruction is split into a op cord (operation to be preformed) and the operand ( data to preform the operation on)
ALU
arithmetic + logic unit – preform arithmetic ( + - ) and preforms logic ( and, or)
Accumulator
holds the result of a calculation and a value that has been input
Address bus
carries the address from the MAR to the main memory
data bus
his carries data/instructions from main memory to the MDR or from the MDR to the main memory
Control bus
this carries data/instructions from main memory to the MDR or from the MDR to the main memory
RAM
random access memory is a form of computer data storage that stores data and machine code currently being used. RAM is volatile which means the contents are lost when power is removed.
ROM
Read only memory is a type of non- volatile memory used in computers and other electronic devices. ROM is non-volatile which means the contents are saved. The main use of ROM is to hold the “boot up” or “start up” instructions.
