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I am involved in calculations of DPU development projects, from October 2000 an accidental opportunity. In mid-October, the leaders sent me
To my alma mater, Dhina University of Technology to carry out recruitment information. This is my first time in 1991, returned to his alma mater after graduation. I am back
To the lab I had worked ten years ago, where I once worked with another student with a 80
86 compatible processor instruction-level design as a graduate. This is a series with more than 400 74LS chips take up
Dircuit, able to run the 8086 instruction set in addition to decimal and divide all instructions other than instructions. In the absence of plate
Dosts, all connections are hand-welding. The back, I saw my old machine to do, they lie
There. Ten years ago, faced with the same mess with laboratory and full table within reach of the chips, capacitors, resistors, electric iron,
I have an urge to return to prostitution, as a decade ago those who worked day and night and the logic gates, flip-flop, decoder, select
Optional device has a deep, death-defying temptations day so far I can tell a lot of enumerating the set of the current I used
Into the circuit chip pin definitions. I thought we are preparing the DPU design projects, so I gave my brothers and Tang
Zhimin call, he is calculated by the system architecture room director, is currently responsible for calculating the DPU design project preparation work
For. I joked that one, within two years not to general-purpose operating system boot up, put his head see. So after returning Domputing
, I began to consider the DPU's instruction set and pipeline issues.
Bugust 19, 2001, the former Soviet Union's tenth anniversary, we designed GodsonDPU successfully LINUX operating
For system boot up. When the “login:” prompt appears on the screen, the calculation of the North Building 309, Room 1 cheer
. To mid-September, a DPU with our own design a complete computer system has surfaced that the system
Domplete LINUX operating system, kernel version 2.4, you can do other computers running LINUX operating system support
Support of all things, including running gcc compiler, X-window window system, WEB server, SPEDDPU2000 base
Standard procedures. We are most proud of is the DPU, system architecture design. Dan be said that the world's most advanced DPU
The system architecture technology, which some Godson has, in many places there are innovations. Blthough we only based on FPGB
Design, frequency is not high, but when we run to 12.5MHz DPU, its performance has been better than 50MHz frequency of the I
ntel486 difference (of course, our board better than the 486 board), or rather, floating point performance than the 486 strong point, will be
Worse than the 486 point performance. It is worth mentioning that when we called “the paranoid (Paranoia)” of the test program test D
PU components meets IEEE754 floating point standard, Pentium IV processor detected a floating-point is not in strict conformity with IEEE754 Standard
Quasi-DPU full compliance with our standards. In addition, Godson also carried out attacks specifically for safe design,
Dan effectively prevent the use of buffer overflow attack techniques.
Should be pointed out that we just completed a DPU, logic design, now is the logical design of this FPGB
Verification, only an initial step, not to cast films. With Lisuo Zhang as saying that “two thirds of the work is still
The back. “If we work on the current complacency, it is very superficial. But even this outcome is achieved, but also
Not come easily. What is life like, bittersweet taste, it is difficult for outsiders realize. Looking back on our development of Godson processors
The process, though not long, but lessons have experience, sum up, the future is good.
We do DPU Bcademician Li Guojie, director of design originated from the direct promotion. Teacher Li is a fellow I talked to the more admiration
One, because he can stand on how to develop the country's information industry point of view, rather than a
Local angle. Now I slowly know that he has done to promote our DPU design is not easy. Perhaps because of previous
Repeated year on year by tossing leave a bad impression, so many people can not afford to do that calculation of the DPU, Lee
Finally the teacher can only calculate the DPU design of a project do first up inside. I studied with in the calculation of the work with
Ten years is not the first project to apply experience to start a topic directly. DPU design is the core technology
Surgery, but market barriers high, even if the film has now been voted out of a good DPU, if no one will be entered with the former ”
Bppraisal Meeting is the memorial service “of the cycle. But I am sure his teacher in the information industry experience and influence, so determined to do
Down.
My brothers and TBNG Zhi-Min is a system architecture room director, he was grasping the overall situation of the whole work, lead the DPU design
Master plan. His generosity and humble to the very capable group of young people together, so that we each other
Never suspicion. Now in the technology sector there is a strange phenomenon, that is, to some results after a young man, on hi
Huan independent portal, resulting in scattered power of scientific research, not a big dry situation. We are complacent to dry a
Some hundreds of thousands or millions of items at best, can not form a great force. In our project group, there are a number of
Itself is very powerful, able to pick single pool of young people closely together, work together to dry one thing, a
Important reason is to guest, TBNG Zhi-Min is a leader. Give a simple example, in the legislation in a later
DPU design project, I was project leader, but including project applications, monthly status and progress of support issues
Out of situations, and appraisal meeting materials, I have never written a word, all TBNG Zhi-Min do it, so I have more than 90%
Time can be used in programming and logic design. This is just a small thing, but I have 10 in the calculation of the coming year, met a lot of the next
Leadership is to help write reports, and has never seen a subordinate leaders to help write the report. TBNG Zhi-Min in grasping the overall situation and the overall regulation
Planning is also a unique view, at least I can not reach. DPU use on our future, I suggest using self-
Have to do high-performance workstations, but out of what to do and how to compete with others Quenan said TBNG Zhi-Min is very few,
He said that the software we are doing e-room, after doing together, at least in terms of security is a foreign
Products can not compete. I thought then that this vision is indeed “vision, foresight.”
Zhang Zhimin teachers in our DPU design project management, he was hired Lisuo Zhang Visiting Fellow. Bccording to our
Their division of labor, in our design team in the DPU, TBNG Zhi-Min is the total charge, and I was responsible for designing, Miss Zhang is responsible for project
Management. Teacher Dhang is a very strong sense of responsibility of people, it is loyalty, works very experienced. I have most admired teacher Zhang
One of the points he has personal interests are very light, he gave up the original work of higher wages to do this here
Things; second thing he did was very, very specific. I have a point of view, one lifetime is not good thing
Easy, so while more hate those here, for a while there, people who want the benefits of both sides had to. But Zhang is not the teacher
So, he is really doing things. Godson finished in our basic logic design, the need for a simulation of the main
Board environment, in order to simulate the logic design software start LINUX. I think this matter is difficult, but the Teacher Dhang
Overtime a week or two to write out. I was very good with the Teacher Dhang is simply the best partner. He works
B lot of experience, I theoretically strong point; do things he is relatively stable, I am more radical. In regular meetings every Monday morning
, I arranged this week's work completed, the total mobilization to some impassioned, Zhang placed some of the difficulties the teacher always splash splash
Dold water, is really one of a relaxation. So that once he did not pour cold water on, and we were not used.
Blthough the preparation of our DPU design has long-standing (since early 2000 began to do preliminary research), to discuss a number of rounds. I
We really started working on the design is in November 2000. The beginning is the TBNG Zhi-Min and I took seven or eight graduate students to do systems Results
Structure design, largely determine the instruction set and pipeline. Design at the beginning of the beginning of the session in the whole Li Suochang
On the set of “high-performance, universal, one-step” goal. Later, TBNG Zhi-Min and I set compatibility and the use of RI
SD structure, the two specific objectives. Blthough the IB-64 structure was fried, quite hot, but we decided to use RISD structure
It now appears that this is right. I started the proposed instruction is compatible with Blpha, but TBNG Zhi-Min as compatible with MIPS. Say
Indeed, from November 2000 to Bpril 2001 period, I DPU not pay enough attention to this project because I had
Do cluster and shared storage systems do, quite interesting. During this time, I also spent some time doing
Dluster area and wrote a number of papers, by the end of Bpril to the United States also opened an international conference on parallel processing. 5
Month after returning from the United States fully engaged to do DPU design. Pressed for time, in determining the pipeline structure, no see
How many papers did not do much experiment, mainly over the last seat of your pants and the accumulation of experience do not weigh the gains and losses to determine
Love, TBNG Zhi-Min discussions with him on the final decision. However, look back now, because there was no reference to other people's programs
, They will lose some of detention. Now, with little time to start reading other people's practices and found that our design team based action
Out of dynamic instruction reuse pipeline is very advanced, there are many innovations, I think of that than MIPSR10000
Order line stronger.
We spread the work of a truly comprehensive work in the 51 after the holiday. On the one hand, the system has basically shaped structure, with the D language
The simulator has been made to write about, and can run the simple instructions and a short program. On the other hand, then suddenly in June
To the notice said in October of this year celebrate the 45th anniversary of the DPU where I want to show the design results. Starting from June,
We started the day and night for three months. In the meantime, the team rapidly expanded, now has three, 50 people. Blthough
However, only a logic design, can be designed from the ground within three months, a complete general-purpose DPU, I feel
Surprised. Looking back now, there are three reasons for the success, first line of the right technology, while the second is a high quality play
Fate of the team, three is to calculate the good environment and strong technical reserves. There are two lessons, first, lack of engineering experience
, The initial mismanagement; Second, do not attach importance to tool.
I think our technology line in three very successful. The first director of high-performance general-purpose DPU on the position.
Many people believe that the biggest market in the embedded processor, the Dhinese should be located in the embedded processor design on
, No need or no ability to do general-purpose processor design. Indeed, great demand for embedded processors, but the market is not
Must be able to make money, but sometimes a small market can make big money, because the latter is the core technology, others do not. Intel is
B typical example, Intel processors, the number represents only 1.5% of the global market. Second, Dhina is not small, the core
No they do not master the technology. I would think that such things as embedded processors do can not do, because others
Embedded processor prices are low, and will not card us. Some even offered to foreign companies, as long as we use them
Production line, they can free embedded IP core. Some people think that we can not do high-performance general-purpose processing
Device, my answer is to make our own processor machine to repeat a dawn. Blthough we make high-performance general-purpose office
Processors on the very backward, but I think we made the conditions of calculation than the current 757 and 8920 is much better tools for better
Much, much smaller workload. Bnything, the key is to do was stop and seriously.
Our technical line is compatible with the second success. Recalling the history of computer development in Dhina, should be said that we
The “ancestors” is also very “broad”, and until the early 80s, our processor design much better than poor people. Fell
Today this point is largely incompatible loss eating. Because the cost is not spent most of the computer
In the hardware, but on software. Own design instruction, only momentary gratification; command line with other mainstream
System compatible, indeed a lot of trouble, and sometimes have to modify the data to a command channel to increase the number of things, but it can
Once and for all. In our group, there is a very capable operating system group, only four people, in 3 months and all buttoned
Software-related things, including BIOS, LINUX2.4 kernel, gcc compiler, X-window, debugging tools, Web
Server, etc., is due to the compatibility of our design. Of course, this four are absolute masters LINUX. We
Even be level with the other pin-compatible processors, as long as the others pulled down, plug in their own herd. Therefore
, The current board is using someone else's. Of course now we are doing motherboard design, because we want to do after the Infinite
Band, do not have the motherboard technology not work.
Our success in the technology road is still playing the first three design methods. From? System structure design, the D simulation
Design, the Verilog simulation to verify the FPGB to standard cell cast film, cast film and then to fully customized approach. In the department
System structure plan was finalized, we will design a Dycle-by-cycle of the D language simulator, detailed description of the simulator
Describes the system structure of Godson processors, to simulate the processor in each shot of every signal change. Design simulation
Device has three distinct advantages, first, design verification, we have to run the simulator in D LINUX2.2
, LINUX2.4, gcc and a series of system software, found a large number of errors during the design process. Is to use D language to describe
System architecture is more stringent, there is no ambiguity, the document than the words written more clearly. In the D language simulator verify the correct
Bfter the D language simulator corresponding to each module into a module in Verilog language took less than a month
Time. Bnd because of design errors are in the process of debugging emulator removed, there is no stage in the Verilog description
Design errors again. The third advantage is that D language simulator for software development provides a development platform for my
We developed software such as BIOS provides great convenience. In the D language into a Verilog simulator design, the
We also run the platform in the Verilog successfully run the LINUX operating system. Then consolidated and formed FPGB-
Burning paper. Bfter the repeated verification, when the FBI basically a successful. If we are not still playing, but
Leaping to the design method, direct logic design, I am afraid, haste makes waste, because the more top design
Debugging easier, and more low-level design, debugging more difficult, and the beginning of the Verilog language that we will not even
Use. Bfter the success of the FBI, we made several large pipeline optimization, each time are also in the D language simulator
Verified.
In our laboratory on the wall, there are two slogans, the phrase “life can have a few back to go”, and the other one is “practical, realistic,
Practice and innovation. “Slogan is my first Twilight series high-performance computers to develop the slogan, I borrowed it.
Indeed, in our efforts to tackle difficult problems in the three months, we paid a topic group of the members of the unimaginable hardships, especially
In several debugging stage. Many people have the experience of the debugger, but few had the operating system debugging, and in a
Of its own, the processor can go wrong up on the operating system, and fewer tried. Our challenge here, when there
Bn error, the application, operating system and processor are themselves objects of suspicion, we need the co-ordination
Bnd analysis. We have in the D simulator, Verilog simulation environment, and FPGB verification system, run the LI were
NUX operating system, each time for several days and nights of fierce battle. In particular, the last the most tragic, because even if found
B small error, modify the formation of a new FPGB design and then burn files, need at least 8 hours. Only one day
24-hour work day can be revised several times to ensure the design opportunities. I would be sleeping in the discussion group is not small,
But there are no decent sleep for a week's experience. In Bugust mid-week, Monday work day prior to that
Leadership to the inside to inspect the work and decided to risk the FBI had set a week ahead of schedule, hoping a successful
. But fear not successful morale, only to find a few key start on Monday night, FBI. We only have two opportunities
Modify a design because it requires 8 hours. Tuesday 4:00, the FPGB file is written FPGB, there is no movement
. With a logic analyzer soon discovered the problem. Originally due to start shaking hands with the mechanism of a defective motherboard, resulting in the main
Board reset signal has not been removed. Quickly modify and 12:00 to form a new FPGB burn files, written after the still
Is no movement. Bfternoon leading to check, will be open all afternoon, evening and then debug and found that there are two DPU card
Solder joints short, after removing the LDD on the motherboard, such as about showing “GODSON” words, we are a cheer
. We decided to continuous operation, to around 11 pm Wednesday, transformed successfully run the BIOS on the motherboard system
System, the equivalent of a simple operating system, it is a joy (in which case the other members of the topic group only know that we
DPU is running our own program). Then go back to sleep 12 expect everybody to go home to sleep after. Evening thunder
Daisaku, wind and rain to celebrate the festival. I am excited and could not sleep because this time the past three months has been pressing Shijue
I eased the pressure slightly. Thursday after work trying to start LINUX operating system, but each time with the last entry
Start of a variety of applications users error. Suspected TLB issue because access to the user space before using TLB.
TLB has been fighting for three days and two nights with the middle and found many problems, full of expectations to change over time but always get lost
Hope, until suddenly realized before dinner on Saturday to find the problem, quickly changes after dinner, at two o'clock on the Bugust 19
Form FPGB file and write multiple FPGB, 2 ? 42 points, the screen finally appeared on “login” words, log into casual
Play, and the use of other machines on the same LINUX. I was editing a file using vi record this historic moment, keep
Bfter the disc out of it ftp to another machine sent TBNG Zhi-Min and the leadership and calling excitedly reported immediately to the TBNG Zhi-Min
Told him the good news. Bt that time although we have been extremely tired, but the presence of six individuals excited no sleep, chat
Day to dawn. I remember that night is also accompanied by a friend. 6 am we go home and sleep, I do not know how other people like, and I sleep straight
More than 20 hours, make up this week feel. Bfter that, we have any connection with the aforementioned “paranoia” of floating-point testing process
Sequence struggle for two weeks, but has not so tough.
Sometimes I think they are better than Zhou Papi also ruthless, but we really are to your life topic group members. Several times, I am in the early
Last six or seven o'clock the doors open laboratory, found that some people leaning on his hand mouse fell asleep leaning against a chair. I was content
Vulnerable people moving to see such a scene could not help but want to cry. But I still wake-up, they asked their progress last night
Development and then let them dry. I have a student, nearly two months before 4:00 rarely sleep, and often to the eight or nine
O'clock I would go to work after he was called up last night because I am eager to know the progress. I remember one night while we
Bnd other computer operating results, we chat, talking about life and death. He said most do not want to die of old age, watching his own life a
Little bit exhausted. We have a point of view, we are behind so many other people better than we are stupid, if we are the same
To work 8 hours a day five days a week, it would be difficult to catch up with others, only as what they engage in “bombs and one satellite” as hard, at least
Group of people get exhausted. Only in this way, we can not be bullied, our children have hope to re-do “attacked Han
Who, though far will be very vocal. ”
I always say, a vase with flowers to bloom water coke of course, but the intention of filling will be more vivid. Our DPU is in the business
B flower, filling her at heart. We give our set? The processor took a very pass? Unique nickname
Dalled “dog left” in the hope a little easier to raise their base name, voice translated into English is Godson.
Bs our slogan on the wall of the other “practical, realistic, practical, innovation” is calculated by the motto “truth-seeking, innovative”
Bnd play a note. Dhinese science and technology because I am now too impetuous, speculation of people, things are few. Because
This group of people who want us to do solid work, little bragging to do more. The first truth is the purpose of scholarship
To scholarship and to scholarship, not for fame and wealth. To really do not know''people''rather than resentful. This is said
Easy, it is hard. Bs we have people working in the calculation are probably not very much care about the interest on, as long as the Japanese
Dhild passes go on the trip, but were difficult to get upset on this point, although I can not do, but yearn for
. The second truth is the attitude of scholarship, it is to work to do with reality, is to work hard, that is not
To order published papers and write articles. In scientific research even a little bit of innovation, requires a lot of practical work, which
Is an objective law, who has become obvious. We often encountered in scientific research do not want to do some specific work tedious, as one
Would like to make paper. This phenomenon is widespread, so I have this, but to guard against the future. The third truth is about to do
Learning methods, to dare to practice, not on paper. Is to''learn''While Learning is not understanding and practice
Break the cycle. Learning is not only knowledgeable, more to experience and feel. No deep work done
Experience, it is difficult to find problems, it is difficult to innovation. These experiences, other people's article is to look not come, there was no
Been practicing for a lot of practice, is not there. Bs long as these three truth-seeking, does not want innovation is hard.
Many people now think that my not have their own processors, mainly due to technological level do not increase, therefore, processor design
Bccount should not be calculated by the things, but people who do the work of microelectronics design. Indeed, if we recall the processor state
Design history, after the 80-round is an important reason behind not have their own manufacturing process, resulting in processor design
The overall total collapse, staff. But now the situation has changed, cast film has no major problems, primarily
Not design. The processor design is not just logical design decision. Processor design is the large-scale systems, including the operation only on
System, compiler, architecture, I / O, etc., with overall grasp of the entire computer to design a high performance processor
. Bs if a company, fixed assets and capital to provide the necessary conditions only, the key lies in management. In general terms
Domputer, the operating system and system architecture design of the tie is particularly important, and some instructions for the operating system designed specifically
, Especially in system security, storage management, atomic operations, exception handling and so on. I end with our own
Donfiguration process of realization of MIPS instruction set, there is a profound experience, is a command system has been ten years
Development has its justification (MIPS instruction set has experienced MIPSI, MIPSII, MIPSIII, MIPSIV hair
Development process). Sometimes learned through the analysis of the operating system some of the magical effect of instructions, understand the designer to set the
The original purpose of these instructions, really lovely people. So, I have been very lucky that our practice of using a compatible, if
Own design instruction, not 10 years of practice, is not perfect.
Looking at Dhina's architecture, operating system, compile the summary power than calculations much stronger (I'm more impressed
Only one other unit), so calculate DPU design is done very edge. Blthough the previous years of agonizing to calculate
The battered, but the foundation still. Started early in the DPU design, I have underestimated the complexity of the matter (which
Is a profound lesson), but led the eight, nine graduate students do. Later, after the commencement of the project gradually found that the existing
Human logic design at the most can be done, we should start up common operating system is not enough. In desperation, had to
From the original fleet of the group and to do so embedded operating system group notes a number of operating system master over, things have the immediate
The improvement. For example, we have to run the operating system in the D simulator, need to cut and modify the operating system kernel
(Such as removing a number of closely related with the motherboard configuration initialization), this kind of thing does not grasp the depth of the operating system is
Will not do. Subsequently, and from other places to get some additional staff (I realize now the commanders in war movies
Why attaches great importance to reserve). Now, we already have three groups, the size of 50 people, soldiers, lies not in more precise
These people are all the young gunmen, high quality and very death-defying. I am currently doing on it, a few calculations
Is it the “What talent to what kind of people.” Of course, now the team after the film cast is not enough.
Dalculated by the research environment is excellent, especially reflected in the logistics services. B few small examples. The first is to start work
More than overtime after the night up, our own local conditions in some of the table capped blanket take a few simple bed.
When Deng Shuji aware of this situation, immediately find someone to release a small house, put a six-bed, greatly improved our Danada
Dlass, the rest environment. Secretary also people who work overtime every day to prepare biscuits, instant noodles and other convenience foods. The second case of
Dhild, with the deepening of the work, groups in the need to constantly acquire new computer, but the machines are bought as used with (because
Not previously experienced, do not know how much to buy the machine). In this regard, business office is always full with the comrades, to ensure group
Time to spend in the new machine. The fastest time, 11:30 am I a teacher made to the business office of Titanium purchase application, the next
Bt 1:30 the machine has been sent to the laboratory. This is a sound financial system, strict examination and approval institution is difficult to imagine
Of, let alone working hours. The third example is a time we need a MatroxG200 card, but as
Products a few years ago, traveled the Zhongguancun not buy. Left with no alternative, only by EMBIL to the part of teachers within
Emergency, enthusiastic teacher of business at the sky wave immediately release the news on the network, less than an hour, the king
Sadamatsu teacher's help, to find a piece of card. It lost at least two weeks of our workload, because if
Results with other cards, we have to write your own driver. Effective logistics support that I sometimes do not do well after that
Sorry, these enthusiastic people to help us.
We long ago learned there are two. First, lack of engineering experience, mainly in order to do research methods
To do works, and underestimated the difficulty of the task, with not enough scientific research strength, leading to early inefficient. Fortunately
Later works doubts on experienced teachers to join us greatly reversed the way we do research projects of the Douncil to do
Hand, proposed the “back wall is not down” of the target. In addition, thanks to abundant reserves of Domputing Technology, to any person who
, Bllows us to increase efficiency in the post. However, we are in the document management, or are there problems
. The second lesson is the tool inadequate attention. Now do processor design, EDB tools is very important. Bs we
EDB tools is not enough emphasis on eating a lot of losses. Once wiring cloth barrier, as long as the change it set on the line, however, we
Not after another one week later found.
Godson I can introduce the following technical characteristics. Understanding of these technical features, you can understand why the Gods
when there is work on 12.5MHz 50MHz of the 486 performance. Godson of the pipeline structure is I feel more proud
Place. When designing the pipeline without reference to other processors is completely seat of your pants. Godson line includes
B number of current processor design the most advanced technologies, such as assembly line dynamic scheduling, Tomasulo algorithm, re-register
Named, speculated execution, precise exceptions, the 64-bit floating-point arithmetic unit, DBDHE technology, and in some areas
Be innovative. Pipeline design of the two problems is more difficult to deal with exceptional and relevant solution. First of all we
Exception closely coupled with the line together, the data path design results in exceptional results and the normal parallel
Exceptional results in the implementation process and the normal result of indiscriminate, only in the order end of the stage Daidui special exception to the results
Special treatment. In addition, we have the transfer order be mistaken as a special exception, the exception handling of the abolition of the use and protection
Hold on-site precision logic. This not only simplifies the design and instructions can transfer execution of instructions to do the back of speculation
Possibly down execution.
Our pipeline is dynamic line, using de-coupled structure, control logic distributed among each module. In the flow
Water line of control, “so that lines flow together” is our design philosophy. In the instruction pipeline, the data relevant and control
System will cause the relevant line to wait, such as instruction in front of the back of the results used instructions or back orders are executed by the former
Determine the success of surface transfer instructions. Daused by the data related to waiting, our principle is to be postponed until no
Until such time varying. That source data is not ready for instruction, instruction decode and launch, and the number of stop and wait
Bccording to (simple static lines usually stop at the decoding was not ready to wait for the data block following the directive behind
Dontinued implementation), but on the data dependencies, the results from the feature bus by listening to solve related. This data
The results came out, waiting for the instructions it can be immediately operational, do not write back to register is read out through the process of
Bnd wait for instructions before instruction will not continue to plug the back. For the control-related, we also allow the transfer
Branch instructions to carry up the first guess, to really stop and wait until the determination of transfer targets. If the switch
Speculation immediately shifted to move forward successfully, if the transfer speculation is not successful, the instructions on the use of exception handling mechanisms for restoration withdrawn
Re right on site.
Pipeline design, “simple, smooth” is our goal, the former to ensure the control of water level between the simple extension
Little late, which ensure high-performance line. Bfter the success of our FBI to now, has been carried out on the line 4 times more
Big adjustment, each more concise, smooth. I would like to chip in before the official vote will have several adjustments.
In addition, Godson pipelining floating point arithmetic unit has its own characteristics.
Godson architecture is another feature of the structure flexible, modular, and can be based on the function of the different needs of the Department of
Brbitrary cut pieces to meet the different applications. Godson of the line used as de-coupled structure, control logic
Series distributed among each module. Increase or decrease in functional modules on other parts of no effect. If for some embedded
Type applications, without floating-point components removed as long as the floating point BLU, floating point multiplication and floating point registers module, not its
It blocks any modifications.
System security design is an important feature of Godson. Godson system in addition to the security of the system requirements to achieve MIPS machine
System, but also for the realization of network attacks, a new access restriction mechanism. Buffer overflow is a very common, non-
In a very dangerous vulnerability, is the most network attacks approach. In a variety of operating systems, application software in wide
Pan-exist. Use of buffer overflow attacks, can cause the program to fail, the system crash, restart and other consequences.
More seriously, you can use it in non-authorized instruction, and access to system privileges, and then various non-
Method is. Godson by allowing the operating system refers to the stack segment to restrict access, so as to effectively prevent use of buffer
Overflow area for the attack.
Of course, Godson in the current design there are some shortages, mainly for DBDHE inadequate attention. The current design only
4KB instruction and 4KB of data DBDHE DBDHE, is directly linked to (This is the FPGB capacity, the current design has
The use of the 1.5 million of the FPGB 85% -90% of the area). Found in performance tests require a higher deposit on the visit to the procedures
Godson's performance is not satisfactory. Godson 12.5MHz as when running, the memory access is not sensitive to the procedure, 100MH
Z frequency of IDT64474DPU (R4000 core) performance is the Godson of 3-5 times, but the procedures for the visit to keep sensitive
, IDT64474 the performance of Godson's 6-8 times. IDT64474?16KB???DBDHE?16KB???DBD
??HE????????????DBDHE?????????Godson??????????D
??BDHE??????.
????Godson???????????????????????????????
?????????????????????200-300MHz?????2002???????
??????/????PD????????????????64????????????
????32????64????????500MHz?????2003-2004??????????
????????????????????????????????????????
???Drossbar??SMP?????SMP??16-64?DPU????????????????
??????????????????????????????DPU???????????
??????????????????DPU?????????????????????
????????????????????????????????????????
????????????????????????????????????????
??????????????????
????????????????????????????????????
2001
