Eloctron, positive hole and Chinese Philosopher

In the lecture of “System LSI”, told us the professor.
“Years ago, there was an incident, that had changed my idea of teaching dramatically.”

“In the examination I made a question – which is the right carrier of nMOS, an electron or a positve hole?”

“I had expected that to this question, 70% of the students could write as electron(電子), 20% would write as positive hole (正孔), and the rest 10% could not write anything.”
“But looking at the answer sheets I was shocked –
Only 30% wrote as 電子, 30% worte as 正孔, and 20% wrote as 孔子.”

孔子 is the name of a famous philosopher in ancient China. In English he might be called “Confucius.”

“孔子 might have brought various ideas, but no electric charge, I suppose. I beg you, my students, please don’t be confused and select one from the two options. Please do not synthesize your own answer. “


Cost performance of processors

The most important thing to think about in choosing processors is cost performance – it is said very often.
How to think about it?
The most important thing we should remember is, the professor is:

A chip of 5mm x 5mm area costs 1000 yen.

“Processing power” is evaluated as a product of “algorithm” and “clock speed”.

“Algorithm” is like “cleverness”. It depends on processor’s architecture. RISC, CISC, Superscalar…they are common examples of architectures.
Parallel processing is effective, but it will be difficult to control too much processes together.

“Clock speed” is like “toughness.” Under the same architecture it depends on “CMOS technology (size of micro structure)” .

By the way, it is very difficult to type “architecture.” I have mistyped it many times.

Busy, no

Yesterday I was so busy that I could not write a post…
No, I don’t like the word “busy”. It might mean as if to write a post were not important, when I had other things to do. Originally I don’t like the Japanese word “忙しい”, and I think “busy” would be its translation.
Instead, there is a japanese expression, “I feel as if my (small) intestine were ripped apart,” oh! splatta! no, “intestine” is meant “a precious part of myself.”
So I dare say, “Yesterday I had so many things, which I had to do immediately, that I did not write a post, though I felt as if my (small) intestine were ripped appart. ”

Multi-purpose Processor?

I learned about types of processors. There are three types, based on their usages.

CPUs are used for many purposes, because they have Operations Systems to control them, and many applications running under the OSs.
This type is called…I learned only in Japanese term and could not find how to say in English . I had guessed it “multi-purpose processor,” but googling for images with that name showed only FOOD PROCESSORS. oh! I think people in Japan don’t use them so often. I have once bought one when I worked in a lab, to prepare suspension of fine calcite particles. It worked very well. It was made in Germany.
Anyway, this type of Processors can be used for many purposes.

DSPs are for a special use. They are mainly used for multi-media, for example, image processing.
They are very good at multiplying and adding.
For example, for such calculation as below:


DSP does by a set of “multiplying two values, and then add another to the product.”
like this way:


80 percent of the DSPs per year are produced by a vendor called Texas Instrument.
“Thanks for DSPs you could play 3D games. You have to appreciate for DSPs before playing,” the professor said.

There are more specified ones so called as “controller processors”.
Each of them is specific for a certain device.
Most popular examples are fuel controllers in cars. For each model of each company a specific processor is designed.
40 percent of controller processors for cars were produced by a japanese vender called Renesas, but unforunately its main factory in Ibaragi was damaged by the latest earthquake, that is many car factories in the world are worried at.

Tornado, Typhoon

I had my Twitter page protected to avoid bots and spammers. Now I use it to follow tweets of some broadcasting companies. CNN is one of them.
Yesterday’s tweets of CNN were very heart-breaking. It reported proceeding of the big tornades over Kansas, Oklahoma…, on real time. It was around ten in the morning here, so it must have been at night there. Imagine how people were terrified by the wind and rain in the dark…
And now also to Japan a Typhoon is approaching. Decades ago May was not yet a Typhoon’s season. Recently each Typhoon has severer damage than in the past.
It’s easy to attribute these increased storms to global warming caused by excess Energy consumption. Human being must decrease Carbon Dioxide’s emission for the future ( If there were not the shameful radioactive contamination, recent effort to save energy in Japan were to be proud of ….). But this argument cannot save people tomorrow, this year.
I feel like natural disaster is not enemies, but difficulties to better as possible get along with. Such a system including technology, politics and economy, etc. would be needed.