Anatomy of a CPU

[Eibro]

Okay-- the thread about overclocking sparked me to ask.
I have a project to do in a few months about microprocessors, does anyone have any links or resources where I can read exactly how/why they work? Yes, i've searched... but I don't know exactly what to search for. There was a pretty good article on howstuffworks.com but i'm still looking for more.

The kind of information Sayeh was spewing off in the overclocking thread is what i'm looking for.

Thanks.

[damonbrinkley]

This is probably a good place to start.

http://developer.intel.com/design/litcentr/index.htm

[Eibro]

Thanks damon.
Could someone please explain to me what some of these terms mean (pertaining to processors and electronic circuts)? Or maybe even point me to somewhere that explains these? The results from Google were vague, and most didn't even pertain to the term.

rise-times
duty-cycles
logic high
high-going edge
logic low
low-going edge
square wave

I've found some good articles (and posts) but i've come across terms such as these which i've no idea about.

[RoD]

i THINK rise-times are how long a processor has to stay in a state of high usage...like how long its under high drain for a particular task.

Say u run winamp an as it loads it takes processor to (made up) 98% use for three seconds.

Then i THINK rise-time = 3;

[Waldo2k2]

keep in mind who your project is targeting...if your teacher or class knows nothing about microprocessors, stay away from the advanced stuff ( you can learn everything else, just don't put it int the project) i think if you cover basic processor logic gates and some easy assembly crap along with bitcode, then you'll do just dandy.
I did a similar project 2 years ago for our physical science class, i went over bitcode, assembly, logic gates, and a taste of basic electronics (transistors would be the topic to hit). Good luck.

[eats only heads]

http://arstechnica.com/cpu/index.html

[Magos]

logic high, logic low
In digital components, a voltage is only considered high or low (1 or 0), this is to reduce the probability of errors since a small change in the voltage won't change the data, but in an analog component it will.

Ie, if you have a 5v component, 0-2 volts may be 0 while 3-5 may be 1 (and 2-3 is a forbidden zone, where you can't tell whether it's 1 or 0).

high-going edge

Most systems are synchrone, meaning that all operations are done in certain clock intervals (ie, on a 500 MHz comp, the operations are done every 1 / 500000000:th second). As you see in the square wave below, there is a 'flank' where the signal goes from low to high, that's the high-going edge, and this is when the operations begin to take place.

low-going edge
The other edge, not particularly important as far as I know...

square wave
I assume that you know what a sine wave is? Well, in digital components you don't wan't the 'curvy form' that a sine wave has. To prevent that, you can use condensators to give it a more rectangular shape.
Why rectangular? Well, as I mentioned earlier the 1/0 status depends on what voltage it is, and due to the forbidden zone you want to spend as little time in there as possible, thus jumping from low to high instantly (and vice versa) prevents that.

See picture:

[Eibro]

Ahh, yes it all makes perfect sense now... thanks Magos. It seems you put a bit of time into that post.

I see why they call it a square wave and why this square wave is never really "square" so to speak...