Military Industry of Great Powers: Build the Strongest Flanker.

Chapter 71 New Hardware Design Patterns

The design of the entire phased array radar is divided into power supply design, high-frequency oscillation circuit, transceiver antenna, ADC/DAC chip, fire control calculation chip, data transmission interface designed based on 1553B data bus, and the data transmission interface just introduced by the country to Italy. The connection of the screen display device is another seventeen items.

Among them, ADC/DAC, fire control calculations, and data link interfaces are very unfamiliar areas to these research units, but it does not mean that they do not have technical reserves in this area.

Transistors have many similarities with electron tubes. Engineers who understand electron tubes can easily understand transistor circuit diagrams as long as they spend some time.

These seventeen items are all based on transistors or chips. With Zhao Guoqing in charge, a lot of material demonstration and component demonstration are eliminated. Not only that, the modern process of chip design is the most important. of.

And many, even highly skilled electrical engineers, feel at a loss when faced with chip design.

Even the 607 Institute, which has the strongest technical strength, is struggling when it comes to ADC chip design.

Zhao Guoqing proposed that the logical design of the chip be separated from the physical design, which opened the eyes of Chief Engineer Gou Jin of the 607 Institute.

The old method is to arrange the circuit one by one, just like the electron tubes, but replace the electron tubes with transistors. This idea is completely outdated. Transistors have functions that electron tubes do not have.

The first thing for these engineers from various units to come to the site is to learn dozens of logic gate circuits. One group is interested in front-end logic design, one group is interested in back-end physical design, and the other group is interested in logic design. You need to know how the physical circuit is laid out, and vice versa, but no matter who you are, you must know the most basic logic gate circuits.

"Through the truth table of the logic function, draw a Karnaugh map, and use gate circuits or chips to construct the relationships in the function. This is the most basic requirement!"

Physical design and logical design are described through logical design languages. Zhao Guoqing did not choose mature languages ​​such as VHDL, and he did not have a computer. He directly used standard format Chinese characters to describe operation types, data types, level logic, and basic ports. List and module code structures are directly described using Chinese characters plus Arabic arrays, and the grammatical structure is formulated.

Although it is a huge project, it is actually just to define the structure-level syntax of VHDL in Chinese characters.

The purpose is very clear, using this language as a bridge to communicate between physical design and logical design.

Logic designers can describe the functions of the module through this language, and physical designers can use specific logic circuits to implement this expression when they see this language expression.

This operation scared Tu Jinda out of his wits, and Ji Hongbo was also shocked when he heard it.

"When I first met him on National Day, he said that he would use computers to design chips. He also said that there was a conference that had just been held abroad. I didn't think much of it at the time. I didn't expect that his research had gone so far. I really can’t imagine what it would look like if this thing really turned into a computer program.”

The ideas suddenly opened up, and everyone was studying and working at the same time.

As for the chip architecture design, which is crucial to the chip, Zhao Guoqing completed it in AVIC's drawing room two months ago.

Chief Engineer Gou Jin of the 607 Institute only now saw the intention of these modules in Zhao Guoqing's drawings. He originally thought they were just part of the system diagram. Now, other than being amazed, he doesn't know what to say. Look at his age!
"The young people today are amazing, amazing!"

At the beginning of the project, there might still be people who were dissatisfied, but a month later, no one would say anything weird.

The position is too high. Technically speaking, everyone including Tu Jinda, Ji Hongbo and others are instantly killed in front of Zhao Guoqing. In fact, from Tu Jinda, the general manager, to the chief engineers and deputy chief engineers, they all came to the meeting one by one. Frontline learning.

There's no way, they don't understand chip design either!Tu Jinda went to Zhao Guoqing specifically and said, "Guoqing, I think your method is very meaningful if it can be compiled into a teaching material!"

Zhao Guoqing smiled and said: "Yes, but this set of things already exists abroad. Computer-aided design language has just been developed abroad. Our research at this time is not much different!"

The ultimate goal is to design our own EDA software. A mere logical expression language is only the foundation of the foundation.

Time passed quickly, and all work was progressing steadily. On December 27 of the lunar calendar, good news came from Tsinghua University Microelectronics. The radar computing chip was successfully taped out. This was the first time that Tsinghua University used a three-micron process to manufacture it. Large-scale COMS integrated circuit, the chip size reaches more than [-] integrated transistors.

This is not the limit of the three-micron process. Zhao Guoqing is wondering if it can be more difficult. Try using 8086 transistors. The computing power of the chip will definitely be significantly improved. After all, Intel used the three-micron process to manufacture the [-] processor.

As soon as Zhao Guoqing arrived, he was pulled away by Professor He Zhenhua and refused to let him go.

"Mr. He, please help me find out what's wrong with this micron manufacturing process?"

Under a photoelectric microscope, the one-micron chip trial produced by Tsinghua University is clearly visible.

"There are many problems. The grooves are blurry. This should not be caused by photolithography. The mask is not precise enough, there is residual dust on the chip, the environment is not clean enough, and the etching depth is inconsistent. It should be caused by uneven spraying or etching. The solubility of the agent is uneven..."

He Zhenhua shook his head. He had been polishing the craftsmanship for several months, but now he seemed to have hit a bottleneck. No matter what he did, various problems would always arise.

Zhao Guoqing said: "Professor He, if you can use stones from other mountains to attack jade, you should try to buy some foreign equipment to learn from, especially the laser mask printer. This thing is so needed."

Rubbing the mask by hand is too tiring, and the quality cannot be guaranteed.

"You think I don't want to, how do you want to buy it?"

Zhao Guoqing didn't say anything. In fact, he actually knew a few well-known brokers in the world, including the ones in Hong Kong. As long as they gave him enough money, they could buy you anything. But at this time, he said no. Come out!

And formal channels!
"Professor He, I heard that Japan is talking to us about building a joint laboratory. I wonder if you can buy some equipment from them in the name of academic exchange for academic research!"

"Approval should be simpler in the name of university scientific research, and by the way, it's about light-emitting semiconductors!"

"Okay, let's give it a try. Anyway, with this budget, a dead horse will become a living horse doctor!"

Zhao Guoqing clasped his hands and said, "God bless, I hope it will come true!"

"Ha ha!"

Zhao Guoqing is really looking forward to it. If the one-micron process is solved, it will be possible to design a chip with a scale of about 50 transistors, and the processing speed will be increased by more than ten times. The phased array radar can not only detect targets, but also calculate the characteristic values ​​of radar waves. It can identify what kind of aircraft the target is and even calculate the best attack angle.

(End of this chapter)