CSCI 109 Lecture Notes - Lecture 2: Booting, Auxiliary Memory, Assembly Language
Document Summary
Input, output, controller, arithmetic and logic unit, memory/storage. Controller + alu = cpu (central processing unit) Central processing unit (cpu: cpu has small amount of temporary memory within. Special register called program counter (pc: performs following cycle repeatedly. Fetch instruction decode instruction execute instruction (repeat) Controller tasks: read an instruction from memory, direct alu to do some arithmetic/logic operation, transfer data from 1 place to another, prep for next instruction to be read, send directive to input or output device. Alu tasks: perform arithmetic operation on contents of registers. E. g. add r1 and r2 and put result in r1 (r1 = r1+r2: perform logical operation on contents of registers. E. g. compare r1 and r2 (r1 < r2?) Storage: addressing and random access: how is storage organized, linear ordering. Each stored item has a number (an address) To retrieve an item, you have to know its number. Storage: modular and hierarchical: analogy w/office files.