# steveWang/Notes

Update notes, again.

steveWang committed Oct 9, 2012
1 parent 0cc157f commit af2b8188270eca51185bea9d904483906a5d43bd
 @@ -212,7 +212,7 @@

Hierarchy

Zero static power: CMOS inverter. Not longer true; power going down, but number goes up. Leakage current ends up being on the order of an amp. Also, increasingly, gates leak.

-

switching current: charging and discharging capacitors. $\alpha C V%2 f$

+

switching current: charging and discharging capacitors. $\alpha C V2 f$

crowbar current: $I_{CC}$, While voltage is swinging from min to max or vice versa, this current exists. All of these things come together to limit performance of microprocessor.

@@ -466,8 +466,8 @@

September 11, 2012

microscope and use undedicated logic and go in with a FIB (focused ion beam) and fix problems. "Metal spin".

Back to chapter two: basic gates again. de Morgan's law: $\bar{AB} = -\bar{A} + \bar{B}$: $\bar{\prod{A_i}} = \sum \bar{A_i}$. Similarly, -$\bar{\sum{A_i}} = \prod \bar{A_i}$. Suppose you have a two-level NAND/NAND +\bar{A} + \bar{B}$:$\widebar{\Pi A_i} = \sum \bar{A_i}$. Similarly, +$\widebar{\Sigma A_i} = \prod \bar{A_i}\$. Suppose you have a two-level NAND/NAND gate: that becomes a sum of products (SoP). Similarly, NOR/NOR is equivalent to a product of sums (PoS).

Now, if I do NOR/NOR/INV, this is a sum of products, but the inputs are @@ -887,7 +887,18 @@

Timing & Delay (H&H 3.5; Fig 3.35,36)

stuff in here that you can play with.

Given that, you have to deal with the fact that you've got this propagation time and the setup time. Cost of pipelined registers.

-

Critical path time, various calculations.

+

Critical path time, various calculations.

+

+

Hazards, Stalls, Delay slots, Three-stage pipeline

+

October 2, 2012

+

:)

+

Let's look at some hazards on the five-stage and then talk about what they +would look like in the three-stage. In the book, 7.51, this is where they +go through and look at what happens with the load word.

+

Must stall or use delay slot.

+

+

Stuff

+

October 4, 2012

 @@ -718,7 +718,60 @@

September 24, 2012

have to do something (aside from paying taxes). Mostly say what you can't do. Never say how to live the good life. BH thinks that serves us ill. Have to make decisions. Often, what you do is different from what you say you -should do.

+should do.

+

+

CS H195: Ethics with Harvey

+

October 1, 2012

+

Star Wars: Idea that was developed and led by Edward Teller (one of the +inventors of the H-bomb, leading scientist at Lawrence Livermore +Labs). Really liked building weapons systems. His idea was to build a +network of satellites in space whose purpose would be to shoot down +missiles aimed at the United States.

+

Lot of reasons to be interested in lasers; one of them was weapons. Reagan +really loved this idea.

+

Talk about how things changed after 9/11?

+

There has not been a day since 9/11 where the United States has been at +peace, but I'm pretty sure this is true, none of those wars have ever been +declared.

+

Prior to 9/11, last attack on US territory was Pearl Harbor (before that +was 1812). The United States is pretty safe against foreign attackers +except for the small group of infiltrated commandos who used to not be much +to worry about, but now they can carry nuclear weapons in their suitcase, +so that's a worry. Hasn't happened yet, but it could.

+

Three thousand Americans died in 9/11? The US kills more civilians than +that every day. It's not hard to argue that the US response to 9/11 has +been disproportionate.

+

Even beyond the egregiously bad military technologies (like these drone +attacks), I would be happy if the United States did not have any military +capability at all. And Americans are so accustomed to thinking that we're +the good guys.

+

Official definition of terrorism: military action taken by a non-government +body. Therefore terrorism is by definition the response of the +disenfranchised people to their situation. Suppose you are in a population +that has no government of its own, has no military, is being oppressed all +the time, and wants to fight back. How do you do it? You can't really +attack anybody's army; there aren't enough of you. So unless you're Gandhi +-- other response: pacifism, and that worked for Gandhi because despite +everything, the British empire had this image of themselves as +paternalistic. So Gandhi was able to shame the British into behaving better +to Indians. The US has no shame, so if you want to fight back, being Gandhi +is a pretty hard sell. The reason the name is terrorist is that you want to +make your enemy afraid.

+

So what's happened in the United States since 9/11? We've become +afraid. And for political reasons of its own, our government has encouraged +us to feel afraid. When you do that, the terrorists have won. The +large-scale way to fight back against terrorism is to decide not to be +afraid and not to flail around attacking every country you've never heard +of because you're afraid. So yeah, I would be happy if we stopped having a +military, period, since I don't trust the US to have a military. Not honest +enough or decent enough or law-abiding enough to have a military. Maybe we +can sign a treaty with Canada to protect us when people come in and invade.

+

I had to say all of that, but I don't want the takeaway message to be "you +should be a pacifist or anti-US". The message is that just as computers are +vitally important to our lives, they are vitally important in war, so some +of you are going to have jobs in which you will be building weapons of +war. If you're in that situation, you need to think extra hard about +whether you're doing the right thing or not.