The latest progress of China's Loongson CPU and products

Loongson CPU (English name: Loongson, formerly known as GODSON1) is a general-purpose CPU independently developed by the Institute of Computing Technology of the Chinese Academy of Sciences. It uses a simple instruction set similar to the MIPS instruction set. The frequency of Loongson 1 is 266MHz and it was first used in 2002. The frequency of Loongson 2 is up to 1GHz. Loongson 3 has not yet been completed, and the design goal is to design multiple cores.

Loongson instruction set :

All 24 CPU memory access instructions come from MIPS

CPU arithmetic instructions (ALU) 10 all from MIPS

All 14 CPU arithmetic instructions come from MIPS

12 CPU multiplication and division instructions come from MIPS

12 from Loongson (8 of which duplicate MIPS instruction functions)

All 20 CPU jump branch instructions come from MIPS

All 15 CPU displacement instructions come from MIPS

CPU special instructions 2 all come from MIPS

All 12 CPU exception instructions come from MIPS

All 10 CPU CPO instructions come from MIPS

The Loongson processor has a total of 131 instructions, of which 119 are from MIPS and 12 are from Loongson (but 8 of them, MULTG, DMULTG, MULTUG, DMULTUG, DIVG, DDIVG, DIVUG, and DDIVUG, duplicate the instruction functions of MIPS.)

Loongson 1

(English name Godson-1) was developed in 2002. It is a 32-bit processor with an internal frequency (also known as: main frequency) of 266 MHz.

Godson-2 was officially completed and released in 2003.

Loongson 2 is a 64-bit processor with an internal frequency of 300MHz to 1000MHz. The 500MHz version has a performance level similar to the 1GHz version of Intel Pentium III and Pentium 4.

The initial version of Loongson 2

The initial version of Loongson 2 was manufactured using 0.13 micron process technology, and more sophisticated process technology will be used in the future. In fact, Loongson 2 is a series, which has evolved through several steps. The known models are 2, 2A, 2B, 2C, 2E, 2F, etc. Currently, the Loongson 2 processor has been used in the low-cost Linux desktop computer (also known as desktop computer): Municator of Yellow Sheep River Company (YSR), with an initial price of about RMB 1,200. Its computers were exhibited at CeBIT in Hanover, Germany in March 2006 and Taipei International Computer Show in June.

Loongson 2E

In June 2006, after the successful tape-out of Loongson 2E in France, STMicroelectronics, the world's fifth largest integrated circuit manufacturer, signed a technology licensing agreement with the Institute of Computing Technology of the Chinese Academy of Sciences to purchase the production and global sales rights of Loongson 2E. STMicroelectronics plans to sell more than 10 million Loongson chips each year.

On September 13, 2006, Chinese scientists announced the successful development of the general-purpose central processing unit chip Loongson 2E. It is a RISC processor that uses the 64-bit MIPSⅢ instruction set, adopts a 90-nanometer CMOS process, has 47 million transistors, and a chip area of ​​6.8mm×5.2mm. The highest main frequency reaches 1.0GHz, the general frequency is 800MHz, and the power consumption is about 5-7 watts. The actual operating frequency is set at 660MHz. In terms of specifications, the Loongson 2E processor has 128KB of L1 cache and 512KB of L2 cache. In terms of performance, its single-precision floating-point operation speed is 8 billion times per second, and its double-precision floating-point operation speed is 4 billion times per second. At the main frequency of 1.0GHz, the Loongson 2E scored 500 points in SPEC CPU2000, and its comprehensive performance reached the level of Pentium III and Pentium 4.

Loongson 2F

Compared with Loongson 2E, Loongson 2F has the following improvements. First, the main frequency is increased by more than 30%. Through frequency screening, there will be products above 1GHz. Second, the power consumption is reduced by about 40% at the same frequency, and many power management functions such as frequency reduction, temperature sensor, and L2 shutdown are added. Third, more system functions are integrated. In addition to the CPU, it also integrates DDR2 memory controller, 66MHz PCI/100MHz PCIX controller, Local IO controller, GPIO, interrupt controller, DMA controller, and some display acceleration functions, which will greatly reduce system costs. Fourth, the package is smaller. The package of Loongson 2E is 35mm*35mm, and that of Loongson 2F is 27mm*27mm. Fifth, the design for testability (DFT) and design for manufacturability (DFM) have been significantly improved, so the chip cost can be reduced.

Loongson 2G

The design specifications of Loongson 2G are equivalent to the single-core version of Loongson 3A. Compared with the previous generation Loongson 2F, the L2 cache capacity, IO bus bandwidth, and supporting bridge chip performance have been greatly improved. Loongson 2G currently runs stably at 1GHz, can provide a better user experience, and is suitable for mobile and desktop markets such as laptops and thin clients.

Loongson 3A

As China's first quad-core CPU with completely independent intellectual property rights, the Loongson 3 processor uses a 65nm (nanometer) process, has a main frequency of 1GHz, and has 425 million transistors. The maximum power consumption of a single Loongson 3A is 15W, with a theoretical peak of 16Gflops. The energy efficiency ratio of each CPU is 1.06Gflops/W, which is more than twice that of the current X86 CPU and has reached the world's advanced level. The Loongson 3 multi-core CPU series products are positioned for server and high-performance computer applications.

Loongson 3A integrates four 64-bit superscalar processor cores, 4MB of L2 Cache, two DDR2/3 memory controllers, two high-performance HyperTransport controllers, a PCI/PCIX controller, and low-speed I/O controllers such as LPC, SPI, UART, GPIO, etc. The instruction system of Loongson 3A is compatible with MIPS64 and supports X86 binary translation through instruction extension.

Loongson 3B

Following the Loongson 3A, the second generation of the Loongson 3 series processors, the 8-core Loongson 3B processor, was successfully taped out at the beginning of this year. Currently, the relevant departments of Loongson are doing further development and testing on this chip. It is expected to be put into mass production this summer.

Loongson 3B still uses a 65-nanometer production process and integrates 8 enhanced Loongson GS464 processor cores on a single chip. It is compatible with MIPS64 and supports X86 virtual machines and vector extensions. It can achieve a computing power of 128G flops at a 1G main frequency. In terms of storage design, Loongson 3B can process up to 64 access requests at the same time and provide a memory access bandwidth of 12.8GB/S. In terms of I/O interface, Loongson 3B implements 2 16-bit HyperTransport interfaces, which can provide an IO throughput of up to 12.8GB/S. The external interface of the eight-core Loongson 3 chip is exactly the same as that of the quad-core Loongson 3. The pins of the two chips are fully compatible, allowing seamless replacement.