Loongson

Loongson

Loongson logo
Designed by	Institute of Computing Technology (ICT), Chinese Academy of Sciences
Common manufacturer(s)	STMicroelectronics
Max. CPU clock rate	266 MHz to 1.2 GHz
Min. feature size	180nm to 65nm
Microarchitecture	MIPS-compatible

Loongson (Chinese: 龙芯; pinyin: lóngxīn, "Dragon chip"; academic name: Godson)^[1] is a family of general-purpose MIPS-compatible CPUs developed at the Institute of Computing Technology (ICT), Chinese Academy of Sciences (CAS) in the People's Republic of China. The chief architect is Professor Hu Weiwu.

Loongson is the result of a public-private partnership. BLX IC Design Corporation was founded in 2002 by ICT and Jiangsu Zhongyi Group. Based in Beijing, BLX focuses on designing the 32- and 64-bit Loongson general-purpose and embedded processors, together with developing software tools and reference platforms.

STMicroelectronics fabricates and markets Loongson chips for BLX, which is fabless.

China uses Linux with its Loongson processor family to achieve technology independence.^[2]

MIPS patent issues

Loongson's instruction set is MIPS-compatible, but the internal microarchitecture is independently developed by ICT. Early implementations of the family lacked four instructions patented by MIPS Technologies to avoid legal issues.^[3]

In 2007, a deal was reached by MIPS Technologies and ICT. STMicroelectronics bought a MIPS license for Loongson, and thus the processor can be promoted as MIPS-based or MIPS-compatible instead of MIPS-like.^[4][5][6]

In June 2009, ICT licenced the MIPS32 and MIPS64 architectures directly from MIPS Technologies.^[7]

In August 2011, Loongson Technology Corp. Ltd. licensed the MIPS32 and MIPS64 architectures from MIPS Technologies, Inc. for continued development of MIPS-based Loongson CPU cores.^[8]

Architecture revisions

Loongson 1

The first revision of the Loongson architecture, the Loongson1 (Godson-232 core) is a pure 32-bit CPU running at a clock speed of 266 MHz. It is fabricated with 0.18 micron CMOS process, has 8 kB of data cache, 8 kB of instruction cache and a 64-bit floating-point unit, capable of 200 double-precision MFLOPS.^[9] Its main focus is on embedded designs such as POS, where 64-bit ability and high speed are unneeded.

Loongson 2

The Loongson 2 adds 64-bit ability to the Loongson architecture. Initially running at 500 MHz, later revisions to Godson 2E were produced that run up to 1 GHz. The Godson 2F, released to market in early 2008, ran at 1.2 GHz.

Loongson 2F

• 4-way superscalar, out-of-order execution, 64-bit MIPS architecture processor core
• Little-endian MIPS III-compatible ISA
• 5 execution units: 2 ALUs, 2 FPUs, and 1 address generation unit (AGU)
• SIMD unit is integrated with one of the 2 FPUs
• Separate 64/64 KB instruction and data L1 caches
• On-chip 512 KB 4-way set-associative L2 cache
• Integrated DDR2 memory controller
• Integrated very simple video accelerator
• Software-controlled dynamic power management
• Max 4 W at 1 GHz

Godson-2G

• 1.0GHz, 65nm CMOS, 3W
• 100M transistors, area 60mm^2
• Single GS464 core

• 64-bit MIPS64 Compatible
• HW support X86 binary translation
• Four-issue, OOO
• 64KB+64KB L1 (four-way)

• 1MB L2 cache
• On-chip DDR2/3 controller.
• 16-bit HT
• PCI/PCIX, LPC, GPIO, etc.

Godson-2H

• 1GHz, 65nm
• Single GS464V core (HD media decoding)
• 512KB L2 cache
• 3D low-power GPU
• DDR2/3 memory controller
• PCIE 2.0 controller
• SATA, USB, GMAC controller
• LPC, SPI, UART, etc.

Loongson 3

Loongson 3B 64-bit microprocessor with 8 cores at 1 Ghz

The 65 nm Loongson 3 (Godson-3) is able to run at a clock speed near 1 GHz, with 4 CPU cores (~15W) first and 8 cores later (40W). In April 2010, Loongson 3A was released with DDR2/3 DRAM support.

Loongson 3B

The updated 8-core 65nm Loongson 3B processor runs at 1.05 GHz, with a peak performance of 128 GFLOPS double-precision, or 256 GFLOPS single-precision.^[10] This is accomplished by having two 256-bit vector processing units in each core. They produce a peak performance of 8 double-precision floating-point fused Multiply-Add results per cycle, or 16 GFLOPS per core operating at 1 GHz.

Hardware-assisted x86 emulation

Loongson 3 adds over 200 new instructions to speed up x86 instruction execution at a cost of 5% of the total die area. The new instructions help QEMU translate x86 instructions by lowering the overhead of executing x86/CISC-style instructions in the MIPS pipeline. With added improvements in QEMU from ICT, Loongson-3 achieves an average of 70% the performance of executing native binaries when running x86 binaries from nine benchmarks.^[11]

Supported software

Unlike processors from Intel, Advanced Micro Devices or VIA Technologies, Loongson does not support the x86 instruction set. The processor's main operating system is GNU/Linux, while in theory any OS with MIPS support should also work. For example, Windows CE was ported to a Loongson-based system with minimal effort.^[12] In 2010, Lemote ported an Android distribution to the Loongson platform.^[13]

Many operating systems work on Loongson.

GNU/Linux distributions:

• Debian, specifically their mipsel port
• Gentoo Linux, specifically their mips port
• Red Flag Linux
• Mandriva Linux, since [2]
• gNewSense, work in progress
• CLFS, MIPS 32/64-bit, Multilib
• UTUTO, work in progress
• EVEREST Linux
• Fedora, work in progress
• ArchLinux, Sources

BSDs:

• NetBSD, evbmips/gdium
• OpenBSD, OpenBSD/loongson
• FreeBSD, kfreebsd-yeeloong

Windows:

• Windows CE

Compiler support

The GNU Compiler Collection (GCC) is the main compiler for software development on the Loongson platform. To target code for the Loongson 2F processor, GCC 4.4 or later should be used with the flags -march=loongson2f and -mtune=loongson2f.^[14] To target code for the Loongson 3A processor, GCC 4.6 or later should be used with the flags -march=loongson3a and -mtune=loongson3a.^[15]

ICT also ported Open64, an advanced optimizing compiler, to the Loongson II platform.^[16]

User applications

Open source applications on Linux Platform can be ported with little effort. Most common open source applications (including OpenOffice.org, Mozilla Firefox, Pidgin, and MPlayer) and applications written for the Java platform are supported.^[17] For .NET applications, an unofficial port of the Mono Common Language Runtime is available online.^[18]

Godson microprocessor specifications

Name / Generation	Model	Frequency [MHz]	Architecture version	Year	Cores	Process [nm]	Transistors [millions]	Die size [mm^2]	Power [W]	Voltage [V]	L1 Dcache [k]	L1 Icache [k]	L2 cache [k]	Performance [ SPECCPU2000]
Godson-1 (embedded CPU)	1	266	MIPS32	2002	1	180	4	?	1	?	8	8	none	19/25
	1A	300	MIPS32	2011?	1	130		529	1		16	16	none
	1B	200	MIPS32	2011	1	130		289	<0.5		8	8	none
Godson-2 (singleCore)	2B	250	MIPS-III 64-bit	2003	1	180	?	?	?	?	32	32	none	52/58
	2C[19]	450	MIPS-III 64-bit	2004	1	180	13.5	41.5	?	?	64	64	none	159/114
	STLS2E	1000	MIPS-III 64-bit	2006	1	90	47	36	7	1.2	64	64	512	503/503
	STLS2F	1200	MIPS-III 64-bit	2007	1	90	51	43	5	1.2	64	64	512
	L2G	900 - 1000	MIPS64	2010	1	65	100	60	<4	1.1?	64	64	1024	?
	L2H?	1000	MIPS64	2011	1	65			4	1.1?	64	64	512	?
Godson-3 (multiCore)	L3A/L2GQ	1000	MIPS64	2009+	4	65	425+	174.5	<15	1.1	64x4	64x4	4096	568/788[20]
	L3B	1050	MIPS64	2011?	8	65	582.6?	299.8?	<50	?	64x8?	64x8?	4096	?
	L3C?	1500+	MIPS64	2012?	16	28	685	?	20	?	?	?	?	?
Godson-T (manyCore)	Godson-T[21]	1000	MIPS32	?	64	28?	?	?	?	?	32x64	16x64	256x16	?
Name / Generation	Model	Frequency [MHz]	Architecture version	Year	Cores	Process [nm]	Transistors [millions]	Die size [mm^2]	Power [W]	Voltage [V]	L1 Dcache [k]	L1 Icache [k]	L2 cache [k]	Performance [ SPECCPU2000]

This list is incomplete; you can help by expanding it.

Loongson-based systems

Lemote FuLoong and YeeLoong with a Loongson 2F microprocessor

Lemote's Fulong MiniPC on top of a CD-ROM drive as reference

In March 2006, a €100 Loongson II computer design called Longmeng (Dragon Dream) was announced by Lemote.

In June 2006 at Computex'2006, YellowSheepRiver announced the Municator YSR-639,^[22] a small form factor computer based on the 400 MHz Loongson 2.

Currently, Loongson boxes that come with a 667 MHz Godson 2E processor or a 800 MHz Godson 2F processor are sold in China at CNY1599 (~US$200) or CNY 1800 respectively without monitor, mouse, or keyboard.

As of July 2008 two manufacturers have announced Loongson 2F products for sale outside China.

• A Dutch company (Van der Led), in April 2008, announced a 8.9" subnotebook, named Jisus.^[23] As of September 2008, however, no orders have been fulfilled, the manufacturer does not respond to inquiries, and the product is no longer on their catalogue.
• A French company (EMTEC), in June 2008, announced^[24] a 10" subnotebook under the brand name Gdium[3], to be sold for "less than 399€" running Mandriva Linux. EMTEC announced the subnotebook would be available for sale in September in Europe, the United States, and China. EMTEC has already shown the devices in public events,^[25] and is reaching out to the developer community through the "one laptop per hacker" program.^[26]

As of November 2008^[update] the new 8.9" netbook from the Chinese manufacturer Lemote that replaced mengloong, Yeeloong (Portable Dragon),^[27] running Debian GNU/Linux, is available^[28] in Europe from the Dutch company Tekmote Electronics.

Loongson 3A laptop

Loongson 3A laptop prototype

Loongson insiders ^[29] revealed a new model based on the Loongson 3A quad-core laptop has been developed and is expected to launch in August 2011. With a similar design to the MacBook Pro^[30] from Apple Inc., it will carry a Linux operating system by default.

In September 2011, Lemote announced the Yeeloong-8133 13.3" laptop featuring 900MHz, quad-core Loongson-3A/2GQ CPU.^[31]

Supercomputers

On 26 December 2007, China revealed its first Loongson based supercomputer with performance 1 teraFLOPS of peak performance, and about 350 GFLOPS measured by linpack in Hefei, designated as KD-50-I.^[32] This supercomputer was designed by a joint team led by Professor Chen Guoliang (陈国良) at the computer science technology department of the University of Science and Technology of China and ICT (the secondary contractor). KD-50-I is the first Chinese built supercomputer to utilize domestic Chinese CPUs, with a total of more than 330 Loongson-2F CPUs, and nodes are interconnected by ethernet. The size of the computer was roughly equivalent to a household refrigerator and the cost was less than RMB 800,000 (approximately USD $120,000, EURO €80.000).^{[citation needed]}

On 20 April 2010, USTC announced Loongson 3A based KD-60-1. The new supercomputer is a cluster of standard blade servers with a total of over 80 quad-core Loongson processors, providing theoretical peak performance of 1 TFLOPS and reduces power consumption by 56% compared to the KD-50-I system that has similar performance.^[33][34]

Dawning 6000

Main article: Dawning Information Industry#Dawning 6000

The high-performance Dawning 6000, which has a projected speed of over one quadrillion operations per second, will incorporate the Loongson processor as its core. Dawning 6000 is currently jointly developed by the Institute of Computing Technology under the Chinese Academy of Sciences and the Dawning Information Industry Company. Li Guojie, chairman of Dawning Information Industry Company and director and academician of the Institute of Computing Technology, said research and development of the Dawning 6000 is expected to be completed in two years. By then, Chinese-made high-performance computers will be expected to achieve two major breakthroughs: first, the adoption of domestic-made central processing units (CPUs); second, the existing cluster-based system structure of high-performance computers will be changed once the computing speed reaches one quadrillion operations per second.

Major events

Development of the first Loongson chip was started in 2001.

On 25 June 2008, Hu Weiwu (chief designer of Loongson processors) gave a keynote speech at ISCA 2008, held in Beijing. The topic of the speech was "Research and Development of Godson processors".^[35]

2010 January, Jiangsu province plans to buy 1.5 million Loongson PCs.^[36]

On 24 August 2010, Hu Weiwu presented a paper on Godson-3C at the Hot Chips 22 conference, held in Stanford, USA. The title of the paper was "GS464V: A High-Performance Low-Power XPU with 512-Bit Vector Extension".^[37]

On 21 February 2011, Hu Weiwu presented a paper on Godson at ISSCC 2011, held in San Francisco, USA. The title of the paper was "Godson-3B: a 1GHz 40W 8-core 128GFlopS processor in 65nm CMOS".^[10]

On 19 August 2011, Dongrui Fan presented a paper on Godson-T at Hot Chips 23 conference at Stanford University (USA), titled "High-Efficient Architecture of Godson-T Many-Core Processor".^[38]

See also

• Sinomanic
• Red Flag Linux
• Debian Linux
• 863 Program
• Ingenic Semiconductor creates a Chinese MIPS II compatible processor used in many applications.

References

1. ^ 龍芯處理器英文品牌定名Loongson
2. ^ "The Loongson-2 MIPS Lemote Yeeloong Netbook". 21 May 2009. http://www.investorvillage.com/mbthread.asp?mb=476&nhValue=152601&nmValue=152625&sync=1&tid=7672239&showall=1. 
3. ^ China's Microprocessor Dilemma(subscription required)
4. ^ MIPS Technologies Licenses MIPS64 Architecture to STMicroelectronics
5. ^ China’s Institute of Computing Technology and STMicroelectronics announce their cooperation on the Loongson processors
6. ^ Godson-3 Emulates x86
7. ^ China’s Institute of Computing Technology Licenses Industry-Standard MIPS Architectures
8. ^ Loongson Licenses MIPS32® and MIPS64® Architectures for Embedded and Computing Applications
9. ^ cpu-museum.de Forum: Godson-1 and 2 Microprocessor Chips, 2005-Apr-20
10. ^ ^{a b} Hu Wei-Wu. "Godson-3B: A 1 GHz 40W 8-core 128 GFLOPS processor in 65nm CMOS". Abstracts of ISSCC-2011. http://isscc.org/doc/2011/isscc2011.advanceprogrambooklet_abstracts.pdf. Retrieved 2 December 2010. 
11. ^ "Godson-3: A Scalable Multicore RISC Processor with x86 Emulation". IEEE. http://doi.ieeecomputersociety.org/10.1109/MM.2009.30. Retrieved 16 April 2009. 
12. ^ 福瓏電腦WinCE 5.0 圖片
13. ^ Company puts Android on laptop with China-backed chips
14. ^ MIPS LS2 Scheduling and tuning
15. ^ "GCC 4.6 Release Series Changes, New Features, and Fixes". Free Software Foundation (FSF). 25 March 2011. http://gcc.gnu.org/gcc-4.6/changes.html. 
16. ^ Open64 on MIPS: porting and enhancing Open64 for Loongson II
17. ^ [1]^{[dead link]}
18. ^ Little-endian MIPS support -- first draft
19. ^ "cpu". http://www.lemote.com/english/cpu.html. ^{[dead link]}
20. ^ "L3A SPEC2000 ratio and rate scores". http://bbs.lemote.com/archiver/?tid-50629.html. 
21. ^ "Godson-T Architecture". http://jcst.ict.ac.cn:8080/jcst/EN/article/downloadArticleFile.do?attachType=PDF&id=9415. 
22. ^ LinuxDevices article about the Municator
23. ^ Jisus subnotebook's Announcement (LinuxDevices, 8 Apr. 2008)
24. ^ Gdium subnotebook's Announcement (4 June 2008)
25. ^ Gdium in a fair at Berlin
26. ^ OLPH
27. ^ Yeelong Specs (LinuxDevices, 22 Oct. 2008)
28. ^ Yeelong 8.9" netbook at tekmote.nl for 335.50€
29. ^ 2011 Godson and the open source community development forum (Shanghai Station) extend the campus of Shanghai University Loongson 3A Mini-ITX motherboards & laptops introduced, configuration, spy photos
30. ^ Loongson 3A Laptop Prototype Photos
31. ^ "Lemote Announced Yeeloong-8133 Laptop". http://www.lemote.com/products/computer/yilong/312.html. 
32. ^ KD-50-I Home page
33. ^ China-made chip takes super step^{[dead link]}
34. ^ 中国“龙芯3A”国产万亿次高性能计算机研制成功
35. ^ Main program of ISCA 2008
36. ^ Soon Loongson in 1.5 million computers
37. ^ "Hot Chips 22: GS464V". http://www.hotchips.org/uploads/archive22/HC22.24.630-1-Hu-GS464V-godson.pdf. 
38. ^ "Hot Chips 23: the puzzle of many cores". http://www.eetimes.com/design/eda-design/4219256/Hot-Chips--the-puzzle-of-many-cores. 

External links

• Loongson Technology Co., Ltd.
• Jiangsu Lemote Tech Co., Ltd.
• Chinese V-Dragon chip now on sale
• China launches Linux 'dragon chip', challenges Intel
• China's first server 'dragon chip'
• BLX IC Design
• Information page on the Godson II
• Article on Chinese development.
• Prof. Li Guojie page
• Wei-Wu Hu, Fu-Xin Zhang, Zu-Song Li (March 2005). "Microarchitecture of the Godson-2 Processor". Journal of Computer Science and Technology 20 (2): 243–249. doi:10.1007/s11390-005-0243-6. ISSN 1860-4749. http://www.springerlink.com/openurl.asp?genre=article&doi=10.1007/s11390-005-0243-6. Retrieved 13 April 2006. 
• Mike Clendenin (20 April 2005). "BLX moves Godson processor up to 64-bit". EE Times. http://www.eetimes.com/news/semi/showArticle.jhtml?articleID=160911551. Retrieved 13 April 2006. 
• AMD and Blx Ic Design Corporation Open New Computing Client Development Center In China AMD pressrelease.
• Chinese design center spins Linux-based "computing client" designs article @Linuxdevices
• Chinese miniPC giveaway targets Apple, Microsoft article @Linuxdevices
• Godson 2E by STMicroelectronics Image
• STMicroelectronics Loongson-2E Datasheet 2007-04-26
• STMicroelectronics Loongson-2F Datasheet 2008-07-28
• STMicroelectronics Loongson-2F/LP Datasheet 2009-01-30
• ICT.CAS (25 January 2011). "Loogson-3A Datasheet" (in (simplified Chinese)). http://www.loongson.cn/uploadfile/file/3Adatasheet2011-02-17.pdf. 
• Godson Roadmap; The Register 2011-02-25
• Photos of Dawning-6000 Blade Server; The Register 2011-02-25
• Dawning-6000 Launch; PHYSorg.com 2011-03-04