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Full Version: Introduction on CPU: From this text to your car radio, he is present !
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CPUs, everywhere and opaque :
From this text, to your TV, to your car radio, and North Korea (also), he is omnipresent.
But who know what is really a CPU?

Despite telling my Pentium from 2000 is 3Ghz, ha ha your 1000$ Core i5 is 1,6Ghz, no, CPU operation knowledge isn't only reserved for a doctorate in computing science, you also !

1 - Who build CPUs ?

For many persons, computer processors (x86 architecture, we will see this further) aren't only conceved by Intel and AMD, but there are also VIA (IDT Centaur) and DM&P Electronics. Now you know it. But let's face it : their performance is derisory and unusable for a daily use (but they can run Windows ~correctly~).
For ARM, the list is so long that is no point to copy it, but they work with a license accorded by ARM. And for RISC (used in the space at 3Mhz Tongue ) and CISC (native), for the opposite reason.
But after the processor designed, he have to be buit literally, semiconductor founders do this : TSMC and Intel locally.

2 - Architecture : what the CPU do ?

All the CPUs have a required specification : the Instruction Set Architecture (ISA).
There aren't a x86 architecture, but a x86 ISA.

2.1 - Architecture : the Instruction Set Architecture

INTEL X86 ISA Ahhh ! Ouch!

All the electronics components needs an input to run. The CPU needs a binary(0/1, see the very good Puggsoy's lesson on bits : suite that is named an instruction.
The instruction is a basic function that is executed by the CPU, but arithmetical or memory functions only, for example you can't make a condition (if) in an instruction, you have to compare 2 registers. Yes, a CPU don't have variables, he have registers, it's kind of like variables, but in a limited number : 16 (general purpose) registers in x86-64 ISA.

2.1.1 - Instruction Set Architecture : Registers

Coming soon !

-Mistakes, details I missed, don't hesitate to tell me !

Update: I interrompt writing this introduction to work another on a real example simple and useful : The SNES DSP coprocessor !