How They Really Work
Osher Lifelong Learning
Institute
University of Illinois, Urbana-Champaign
Scott Badman, Instructor
Session 4: The Centeral
Processing Unit (CPU)
October 7,
2013
This evening we will see how an extremely simple, conceptual Central Processing Unit (CPU) works, from the transistors up.
Core Concepts
A computer is a machine that does logic.
The fundamental principles that computers use to operate are amazingly simple -- the complexity is only in the implementation.
The logical equivalence of hardware and software
Computer engineers are primarily interested in performance, efficiency, and
cost.
They will do anything that works, no matter how complicated or arcane for human beings.
However, they have no motivation to make computers more complicated or arcane than necessary.
Top computer engineers who make the important decisions are usually very smart
and do a really good job.
The Central Processing Unit implements logic, and
therefore arithmetic.
The Central Processing Unit consists solely of transistors that form simple logic gates.
Virtual Machines can create a complete computer, in software, on a hardware computer.
Any software program can (in theory at least) be implemented directly on a hardware chip.
Topics
The Central Processing Unit (CPU)
Resources
CPU Introduction (Power Point)
CPU Introduction (pdf file) (Much faster download over the Internet)
CPU Execution, data only with calculator pictures (Power Point)
CPU Execution, data only with calculator pictures (pdf file) (Much faster download over the Internet)
CPU Execution, fetch and execute (Power Point)
CPU Execution, fetch and execute (pdf file) (Much faster download over the Internet)
CPU Execution, fetch and execute (Power Point) (review)
CPU Execution, fetch and execute (pdf file) (review) (Much faster download over the Internet)
Memory, ALU, and Control Circuitry (Power Point)
Memory, ALU, and Control Circuitry (pdf file) (Much faster download over the Internet)
CPU Execution, all busses and control lines (Power Point)
CPU Execution, all busses and control lines (pdf file) (Much faster download over the Internet)
CPU Execution, first full SUB execution (Power Point)
CPU Execution, first full SUB execution (pdf file) (Much faster download over the Internet)
CPU Execution, last full JLT execution (Power Point)
CPU Execution, last full JLT execution (pdf file) (Much faster download over the Internet)
