computer systems and cpu

computer system

hardware and software that work together to process data and complete tasks

hardware

physical stuff that makes up your computer system

software

programs or applications that a computer system runs

embedded systems

computer systems designed for a specific task built into a larger computer system

dedicated to single task

easier to design

cheaper to produce

more efficient at doing their task

cpu

brain of computer system

processes all the data and instructions that make system work

control unit (cu)

overall control of the cpu

manages fetch decode execute cycle

controls flow of data inside the cpu

arithmetic logic unit (alu)

performs arithmetic calculations and logic operations

contains accumulator register

cache

fast memory in cpu - slower than registers but faster than ram

stores regularly used data for easy access when it’s needed

low capacity and expensive compared to ram and secondary storage

registers

temporarily hold tiny bits of data needed by the cpu

quick to read/write

program counter, mdr, mar, accumulator

program counter

holds memory address of the instruction for each cycle

accumulator

stores intermediate results of calculations in the alu

memory address register

holds any memory address about to be used by the cpu

address might point to data or a cpu instruction

memory data register

holds the actual data or instruction

may have been fetched from memory or be waiting to be written to memory

fetch

copy memory address from program counter to the mar

copy instructions stored in mar address to the mdr

increase program counter to point to the address of the next instruction for next cycle

decode

instruction in the mdr is decided by the cu

cu then prepesres for the next step

execute

instruction is preformed