COM SCI 31 Lecture Notes - Lecture 2: Arithmetic Logic Unit, Memory Address, Von Neumann Architecture

• School: UCLA
• Department: Computer Science
• Course: COM SCI 31
• Professor: Smallberg, D.A

Document Summary

Larger and larger, cheaper and cheaper, but just integers: cpu. Working example of cpu: 0:21004, 1:11005, 2:22006, 3:99999, 4:00042, 5:00013, 6:37285, accumulator:65835, instruction counter: 000. Cycle 2: 11 005, operation code address in memory 00013, 11: add the number at the indicated memory address to the accumulator, replace 00042 with 00013+00042=00055. Note: accumulator get replaced, memory remember the number without changing. Cycle 3: instruction counter: 001 >002, 22 006, operation code address in memory 37285, copy the number in the accumulator into the indicated memory address, memory 6: 37285 >00055. Cycle 4: 99 999, operation code address in memory, 99: halt. In readable sentences: load price into acc, add fees, store acc into total, halt, input/output. Advanced/ efficient ways of input/output: von neumann architecture. Encode the instruction in numbers stored in the memory. Machine language: working example of cpu. 21: copy the number at the indicated memory address into the accumulator. Arithmetic/ logic unit: add/subtract/compare >do work for the cpu.