Apr 19, 2020 21:00:00

Why is it difficult to develop a new processor with RISC-V?

There are several types of

instruction set architectures that systematize the instructions that a processor can interpret and execute, typically x86 and ARM . RISC-V , which is one such architecture and is developed in open source, is attracting attention as it has the potential to line up with x86 and ARM, and some companies are embarking on the development of their own processors that adopt RISC-V. Semiconductor Engineering , which handles news about semiconductors, summarizes the opinions of semiconductor company executives on the proprietary development of new processors.

Why It's So Hard To Create New Processors
https://semiengineering.com/why-its-so-hard-to-create-new-processors/

RISC-V was started by the University of California, Berkeley in 2010 and is now a project in which major IT companies such as Google and HP also participate. You can find out more about RISC-V by reading the article below.

RISC-V is expected to be a technological innovation since 'Moore's Law' --GIGAZINE

'Processor verification' is said to be a major obstacle in the development of new processors. 'To truly complete a processor's validation, everything that could run on it,' said

Paul Cunningham , vice president of Cadence Design Systems , an American semiconductor development software company. You have to run the software, which is virtually impossible. Processor verification is very difficult. '

For low-end processors mainly installed in embedded devices such as edge devices , the structure is simple because structural flexibility, development cost, and low price are required, and it is relatively easy to verify the processor. thing. The open source RISC-V is said to have the flexibility to implement minimal configurations and has strengths in the embedded domain.

However, the story is different for high-end CPUs that are installed in ordinary PCs. It requires complex features such as multi-core and

speculative execution , and sometimes that complexity can lead to vulnerabilities . Valtrix Systems co-founder Shubhodeep Roy Choudhury said it's very difficult to implement and validate multi-core and speculative execution, as well as virtualization and FPUs , while taking security into consideration. indicate.

The cost of verification is also one of the barriers to developing a new processor. Cunningham points out that major processor vendors have huge laboratories and extensive expertise. Although RISC-V is open source and can be used by anyone, it is an architecture that specifies only an instruction set, so the hardware implementation must also be verified. Hardware validation also becomes more expensive as more complex features are added to the processor, said Colin McKeller , vice president of Imagination Technologies .

In addition, specialized know-how is required for verification. About 20 years ago, there were more companies developing processors than they are now, but as a result of many acquisitions and mergers, know-how has been concentrated on specific companies. Hagai Arbel , CEO of Vtool , which develops semiconductor verification software, also said, 'Even with a very small and simple processor, design verification requires specialized knowledge, and it is a mistake that a different approach from other designs is required. There is no such thing. ' In addition, companies with concentrated know-how tend to be reluctant to publish papers and tools, and it is very difficult to obtain know-how from the outside, McKeller said.

'Hiring people' is the best way to overcome these barriers, Cunningham said. On top of that, he said, 'We should narrow down the necessary functions, remember the open source spirit, and spend time and effort on new things.' In addition, Imperas CEO Simon Davidmann said, 'In a situation where you can get a good processor without developing your own processor, it is important to ask yourself' Why do you need to develop your own processor? ' And if the goal is to add interesting structures or custom instructions, then RISC-V processor development would be correct. '

The RISC-V community is working to overcome these barriers, but given that even major processor vendors have left unexpected bugs and vulnerabilities despite years of experience, processors. It has been concluded that the entire development of is unlikely to replace open source.