Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [cpu]

The CPU, the Central Processing Unit, is known as the heart of the computer. It is responsible for carrying out the instructions of a computer program by performing the basic arithmetic, logical, control, and input/output (I/O) operations specified by the instructions.

A typical CPU consists of:

  • an ALU, or Arithmetic and Logic Unit, which handles addition, subtraction, multiplication, division, and logic operations
  • a register file
  • a control unit, which fetches, decodes, and executes instructions

It is usually connected to memory containing both program and data, and control ports for memory and other peripheral parts.

See also:

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Why is there no `nand` instruction in modern CPUs?

Why did x86 designers (or other CPU architectures as well) decide not to include it? It is a logic gate that can be used to build other logic gates, thus it is fast as a single instruction. Rather than chaining not and and instructions (both are…
Amumu
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Why not make one big CPU core?

I don't understand why CPU manufacturers make multi-core chips. Scaling of multiple cores is horrible, this is highly application specific, and I am sure you can point out certain program or code that runs great on many cores, but most of the time…
wav scientist
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For mainstream computing what are the practical advantages of 64-bit register size CPUs given the needs of today and the near future?

I understand one of the limitations of 32-bit processors is the inability to easily address more than 4GiB of RAM, which is a present day need even for mainstream computing on phones, tablets and laptops. What are some other mainstream computing…
satur9nine
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Can a CPU be notified that it's about to lose power?

If I have a desktop computer and I pull out the power cord, are there are a few million CPU cycles that still happen before it completely runs out of energy? There could even be a capacitor on the motherboard to extend that to a few billion. Do CPUs…
user81748
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Difference between superscalar and multi-core?

I can´t seem to grasp this, what is the difference between superscalar and a multi-core processor? I keep mixing them up, so some simple points on what they do would be great.
marsrover
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CPU/Processor error rate in calculations

Does Intel or AMD publish specifications about the rate at what failures in calculations can be expected on their CPUs? I would suspect it would be very age and temperature dependent, but surely there must be some kind of numbers available? I'm not…
edA-qa mort-ora-y
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What is a 2 to 4 line decoder?

Could I get a basic description of a 2 to 4 line decoder? I've tried looking online but they make it too complicated for me to understand.
Jack Reilly
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Does CPU pipelining always imply a multicycle datapath?

I'm studying the MIPS CPU and I have a very basic question about the datapath. Since the MIPS CPU uses a 5 stage pipeline, that means that the pipeline is using a multicycle datapath, correct? If a CPU has instructions where the Cycles Per…
Henley
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What is the function of the capacitor and the diode here?

This photo: is taken from the book: The Intel Microprocessor Family: Hardware and Software Principles and Applications, page 298. This is a 8284 (clock generator) for the 8088 microprocessor. What is the function of the capacitor and the diode…
ammar
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Implementing multiplication

I'm trying to implement multiplication in a cpu I designed. I'm trying to achieve this with some conditions. I only two general purpose registers Rx and Ry and these instructions: Add Rx, Ry [Add take Rx and Ry to ALU and returns result…
John Smith
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How does a CPU work?

I am curious, generally speaking, as to what are the physical processes behind the workings of a CPU. I understand that the reason why computers use binary is because it means that data can be stored magnetically by direction, or electrically by…
cm007
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Why does capacitor charge slowly but discharge quickly?

I've designed this circuit using Multism 10.1 : This circuit is part of clock generator for 8088 uP: Why does the wave of ch1 of Oscilloscope which represent the voltage across the capacitor take this form? What is the relationship between that…
ammar
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What kind of building blocks are most transistors in current generation CPU's dedicated to?

When you look at the newest consumer AMD and Intel chips with billions of transistors, what the (Pareto) breakdown of building blocks used? Or asking in another way, if you zoomed into a modern CPU what would be the building-block type breakdown per…
Wuschelbeutel Kartoffelhuhn
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Simple "Computer Design" project

Im trying to learn more about the depths of computer design, I;m talking about CPU design. Down to the very very low level of Computer Organization. I took a few EE (I did a CS degree so...) classes in college, but it was mostly Introduction and…
user3073
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Best practice to implement wait state on 6502 CPU

What is the best practice to implement wait states on a 65(C)02? Are there any schematics to use as reference?
ozw1z5rd
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