Indigenous microprocessor on RISC-V ISA, “Shakti” leads the way
BENGALURU — When Krste Asanović, chief architect and leader of the team at UC Berkeley that defined the open RISC-V ISA recently visited India for the first time, he was absolutely confident that he would come again.
Not just because he loves Indian food which he had fallen in love with during his childhood in England but because there has always been a long-standing and strong Indian connection with IIT, Madras which has been working on RISC-V through its Shakti Project.
Now the Indian connect just grew stronger after Krste’s co-founded company, SiFive acquired Bengaluru-based Open-Silicon, a system-optimized ASIC solution provider which would now start focusing more on RISC-V. Its customised ASIC work would also simultaneously continue. SiFive, the first fabless provider of customized semiconductors based on the RISC-V and founded by some of the team members from Berkeley, helps organizations turn semiconductor designs based on the open-source RISC-V instruction set architecture (ISA) into chips.
“Even before we announced publicly and started pushing out RISC-V, there were emails from India asking us if they could use the open ISA. From the beginning in India, we had the Shakti team – the connection was through MIT,” Asanović, said.
And just a couple of months after his visit the Shakti team had announced its first indigenously developed and manufactured microprocessor, in the Pruthvi series.
“The momentum as far as RISC-V is concerned is massive and we have over 110 companies and organisations as members such as IBM, Google, Qualcomm, Samsung, Western Digital, Nvidia and Huawei among others doing projects on RISC-V,” he pointed out.
It is also picking up in India at a similar pace since the Indian government has officially adopted RISC-V as the national ISA, underscoring the power of the architecture and its capacity to enable innovative commercial and military application.
“In 2013, there was an Indian processor initiative that was funded by the government and they were looking for an ISA that would give them independence from Intel’s X86 and ARM’s ISA – proprietary and non-Indian companies. They wanted to control their own ISA and looked at various options and eventually decided on RISC-V – as national ISA for India. The goal was to build your own implementation without any control from outside. And, the two critical factors – security and local manufacturing – also bolstered RISC-V’s chance of adoption,” said Asanović.
The second one is to help the Indian economy in terms of semiconductor imports becoming a large fraction in the trade of balance in India. “India wants to produce semiconductors within the country and by using RISC-V they don’t have to pay for licence – start-ups as well as commercial entities can build the cores in India at a low cost without having to pay licence fee to anybody,” he added.
The “Shakti” Connection
Researchers at Indian Institute of Technology, Madras (IIT-M) have designed and booted up India's first microprocessor, “Shakti” (meaning power), which could be used in mobile computing and other devices.
According to IIT-M, the Shakti microprocessor can be used in low-power wireless systems and networking systems besides reducing reliance on imported microprocessors in communication and defence sectors. The microprocessor can be used by others as it is on par with international standards, researchers said.
The Shakti family of processors was fabricated at Semi-Conductor Laboratory (SCL), Indian Space Research Organizations (ISRO) in Chandigarh, making it the first 'RISC-V microprocessor' to be completely designed and made in India, IIT-M said.
Shakti is an open-source initiative by the RISE group at IIT-Madras, which is not only building open source, production grade processors, but also associated components like interconnect fabrics, verification tools, storage controllers, peripheral IPs and SOC tools.
The Shakti project is building a family of 6 processors, based on the RISC-V ISA. It will also develop reference SoCs for each class of processors, which will serve as an exemplar for that family. While the primary focus of the team is architecture research, these SoCs will be competitive with commercial offerings in the market with respect to area, power and performance.
Apart from front-end design, Shakti I is also actively working with partners to develop a base VLSI flow (front and back-end) for a large part of the ecosystem. While all the tools might not be open-source, the scripts and environment to plug-in SHAKTI components will be released in open-source.
Source code of all the components of the Shakti project are open sourced. "With the advent of Digital India, there are several applications that require customisable processor cores. The 180nm fabrication facility at the Semiconductor Corporation Ltd., (SCL) Chandigarh is crucial in getting these cores manufacturers within our country," said Prof. Kamakoti Veezhinathan, Lead Researcher, Reconfigurable Intelligent Systems Engineering (RISE) Laboratory, Department of Computer Science and Engineering at IIT-M.
The other crucial aspect of such an indigenous design, development and fabricating approach is reducing the risk of deploying systems that may be infected with back-doors and hardware Trojans.
This development will assume huge significance when systems based on Shakti processors are adopted by strategic sectors such as defence, nuclear power installations, government agencies and departments, according to an IANS report.
According to newspaper reports, the Shakti processor family targets clock speeds to suit various end-user application devices such as various consumer electronic devices, mobile computing devices, embedded low-power wireless systems and networking systems, among others.
The project is funded by Union Ministry of Electronics and Information Technology.
The impact of this completely indigenous fabrication is that India has now attained independence in designing, developing and fabricating end-to-end systems within the country, leading to self-sufficiency, IIT-M claimed.
With a large percentage of applications requiring sub 200 MHz processors, the current success paves the way to producing many hand-held and control application devices.
In July 2018, an initial batch of 300 chips, named RISECREEK was produced under Project Shakti, that were fabricated at the Multinational Chip Manufacturer Intel's facility at Oregon, USA, that successfully booted the Linux operating system. Now, the fabrication has been done in India, the reports added.
Interestingly, a start-up, InCore Semiconductors founded by one of the team members, Neel Gala plans to design and license RISC-V-based processor cores as well as deep-learning accelerators and SoC design tools.
— Sufia Tippu is a freelance tech journalist based in India contributing to EE Times India