Li Yixuan inadvertently turned to the door of the laboratory and found that the door was already full of people, all of whom were students brought over by Yu Youcheng.

After Yu Youcheng joined the Oranges company, he would definitely not let go of his student Li Yixuan, so he proposed to him to teach in another place, and I would provide the place without money, and it was not enough to teach students only to talk about theory, but also to practice. I have a spare house next to my chip factory, and your students can just apply what they have learned.

Yu Youcheng, who has been in the society for many years, would not know what the other party had in mind, but he didn't say anything, and moved here directly with his students.

Li Yixuan first took them to see their chip factory, a tall and tidy modern factory, a fully automatic robot, and an intelligent assembly line, as if they had entered the factory of the future, and these students immediately fainted.

Li Yixuan has not provided them with accommodation, of course it will not be very good, but it is not bad, the dormitory is built according to the standard of the capsule hotel of the RB standard of later generations, each floor has a high-standard bathroom, and there is a TV room on the top floor.

In fact, according to the standards of RB Capsule Hotel, there is an LCD TV in each capsule bedroom, but now there is such a thing, so a TV room was built on the top floor to enrich the spare time life of students.

High-standard accommodation hotel, high-standard laboratory. Yu Youcheng and the students he brought with him stayed here.

His students are very diligent, they go to the chip factory in the morning to help, and ask the engineers inside for advice (humanoid robot engineers), they want a sponge that has been dry for a long time, and they can't wait to learn all the knowledge and understand all the equipment in the factory. In the evening, they also take the initiative to review and digest what they have learned during the day.

In this way, under the dual teaching of theory and practice, this group of students has grown rapidly.

Li Yixuan and Yu Youcheng's discussion on RISC and CISC has long attracted the attention of these students, they feel that the discussion between the two is too knowledgeable, it has long been beyond the scope of their knowledge, they all want to listen, but they are afraid of disturbing the two, so they all stand at the door of the laboratory and listen quietly, and everyone is still holding pens and notebooks to record the conversation between the two.

These people are the future of the Oranges company, and Li Yixuan will definitely not drive them away, so he said to them: "If you want to listen, come in and listen, you can't really listen at the door." ”

As soon as they had finished speaking, they came in in a hurry.

Looking at this group of students, Li Yixuan asked, "How much did you understand the conversation I had with Professor Yu just now?" ”

All of these students look at me, I stare at you, and none of them come out to speak.

Li Yixuan sighed, although this knowledge is very common in later generations and can be found on Baidu, it is still too advanced for them now.

A girl raised her hands, "Teacher, excuse me." ”

"Say." Someone finally asked a question, and Li Yixuan felt very relieved.

"What are RISCs and CISCs?"

Li Yixuan almost choked back his internal injuries, so he didn't even know this, how did your teacher teach you? Turning his head to look at Yu Youcheng.

"This ......" Yu Youcheng said a little embarrassed: "RISC is too advanced for them at the moment, and I didn't tell them about it." They were only given a few lectures on the basic design fundamentals of CISC. Moreover, the mainland has been isolated from the rest of the world for too long, and they do not know the concepts of RISC and CISC. ”

understood, he felt that Yu Youcheng was right, not to mention these students, even if a big bull like Yu Youcheng didn't understand RISC, how could he tell them, otherwise he would be misleading people's children.

Li Yixuan walked to the blackboard on the side, wrote RISC and CISC on it with chalk, and began to give everyone the origin and difference between the two, as well as the advantages and disadvantages of the two.

"Students, CISC is the abbreviation of Complex Instruction Set Computer, which translates into Chinese as Complex Instruction Set Computer. We all know that modern electronic computers have gone through the era of tube computers and transistor computers, and have developed into the era of integrated circuit computers today. And the first integrated circuit computer of mankind was CISC...... Early computer components were more expensive, with low clock speeds and slow computing speeds.

In order to improve the speed of computing, people have to add more and more complex instructions to the instruction system to improve the processing efficiency of the computer, which gradually forms today's complex instruction set computer system...... We all know that the basic logic of a microprocessor is a circuit that runs instructions, and any program of a computer is composed of more or less basic instructions, and the instructions themselves are composed of several microoperations, such as adding and subtracting two binary numbers, or sending the result into a register, etc.

If you know assembly language or machine language, you should know that these basic instructions are called microcode of microprocessors, and the more instructions there are, the more logic circuits are required to complete the microoperations, and the more complex the structure of the chip...... Each processor developer can define their own set of instruction systems, but if the instruction systems are not the same, the instructions that make up the software are not the same, so the software is not compatible.

In the seventies of special-purpose computers, this situation can be said to be very common, each computer manufacturer has independently developed instruction systems, microprocessors, computing machines and software, and the software and hardware products of different manufacturers cannot be used compatibly, the reason is that the instruction system of microprocessors adopts different definitions.

…… However, although there were many types of instruction systems at the time, they all belonged to the CISC architecture, and no matter how CISC was designed, they all had a common feature, that is, the number of instructions was large and bloated, and each instruction was in the same priority regardless of the frequency of execution, and the advantage was that the programmer was relatively easy to program. However, its fatal drawback is that the execution is inefficient, and the processor's transistors are occupied by a large number of inefficient instructions, and the resource utilization is quite low.

Why CISC is inefficient, we have to start from the source of CISC...... In the early days of CISC, the core instruction function was not complicated, and the instruction itself was very short and concise, such as an addition instruction, no matter how long it was, it was limited. However, with the development of semiconductor technology, various fields are keen to develop their own special instructions, combining the originally refined instructions to form a large and complex function system

…… The current processor can only process the second instruction after processing one instruction, and the instructions to be processed can only be queued up. If every instruction is too long, the wait time will be long. It doesn't matter if you wait for a long time, the key is that the circuit called by each instruction is not consistent, and some operations call different functional circuits at the same time, which is good and does not take up time.

However, some complex instructions repeatedly call a hot circuit, the hot circuit is overloaded, and the other circuits are empty and can't do anything else, wasting the processor hardware architecture.

For example, if the whole school gathers and a class of students goes out through the gate, if there are more people in the class, the more time it will take to go out. If everyone is still fighting when going out, and a few people are scrambling to get out first, these people are blocking the door for a long time, and the people behind can't leave if they want to, and the whole class will delay even longer when they rush to the playground to gather.

The inefficiency of complex instructions is low, and it is low here. Therefore, some people put forward RISC, that is, Reduced Instruction Set Computer, the concept of reduced instruction set computer, the essence of its design is to simplify the computer instruction function, so that the average execution cycle of instructions is reduced, so as to improve the working frequency of the computer, and at the same time a large number of general registers are used to improve the speed of subprogram execution......"

Li Yixuan talked eloquently in front of the blackboard, in-depth and simple, easy to understand, and clearly organized, and everyone could understand it. And Yu Youcheng was even more frightened, he found that the young man on the podium had reached a level of mastery of RISC and CISC, and his knowledge was far beyond him. It was only then that he truly believed that Li Yixuan was able to design RISC.

“…… In addition to what I just said, there is another item that also affects the operational efficiency of the CISC......"

Before Li Yixuan finished speaking, there was a sensation below! Also, it seems that there are really a lot of problems with CISC, and everyone is talking about it one after another.

Yu Youcheng was also very interested, and he also wanted to know what else would affect the efficiency of CISC's operation, so he coughed, and the audience left quietly, waiting for Li Yixuan to continue.