The document discusses the next ten years of RISC-V development. It notes that while specialized ISAs come and go, general purpose ISAs can last for decades. In the next ten years, RISC-V aims to become the industry standard ISA across all computing devices. To manage diversity, RISC-V uses a modular design with bases and extensions. The Technical Steering Committee will focus development on key application domains and release architecture profiles to guide the ecosystem. New security threats and applications will emerge, requiring ongoing development and specialization of RISC-V.

1. The Next Ten Years
Krste Asanovic
UC Berkeley, RISC-V International, & SiFive Inc.
krste@berkeley.edu
RISC-V Summit
December 9, 2020

2. General-Purpose ISAs last for Decades
§ The original ISA, IBM 360, now 56 years old
§ Intel x86 now 42 years old
§ ARM now 35 years old
§ RISC-V now 10 years old
§ All in active development, with new hardware
implementations in advanced technologies
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3. Special-Purpose ISAs come and go
§ Array processors
§ Network processors
§ Image processors
§ DSPs
§ GPUs
§ AI accelerators
§ Types of specialized processor persist, but rare for
hardware ISA to last more than a decade
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4. A Lot Happened in Last Ten Years
§ Deep learning emerged
- e.g., AlexNet 2012
§ Whole new classes of security challenge appeared
- e.g., Meltdown/Spectre 2017/2018
§ These are now the primary topics of research in
architecture community
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5. In Next Ten Years
§ New security threats will arise, but don’t know what
§ New application areas could become prominent, but
don’t know which
§ We’ll need to at least start on RV128 base definition
§ RISC-V will increase adoption throughout computing
- Free and open + simple modular design
§ New specialized processors, but more based on RISC-V
rather than specialized and/or proprietary base
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6. Our Modest RISC-V Project Goal
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Become the industry-standard ISA for all
computing devices
This is happening!
Far faster, more domains, than anyone predicted
Demand at every performance level (low to ludicrous)
Demand for all features of all other ISAs ever built!
Using a new community ISA spec development model

7. RISC-V Ecosystem
Software
Hardware
ISA specification
International
Compliance
Golden Model
Open-source cores:
Rocket, BOOM, RI5CY,
Ariane, PicoRV32, Piccolo,
SCR1, Shakti, Serv, Swerv,
Hummingbird, …
Commercial core providers:
Alibaba, Andes, Bluespec,
Cloudbear, Codasip, Cortus,
InCore, Nuclei, SiFive,
Syntacore, …
Inhouse cores:
Nvidia, WD, +others
Open-source software:
Gcc, binutils, glibc, Linux, BSD,
LLVM, QEMU, FreeRTOS,
ZephyrOS, LiteOS, SylixOS, …
Commercial software:
Lauterbach, Segger, IAR, Embecosm
Micrium, ExpressLogic, Ashling,
AntMicro, Imperas, UltraSoC …
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8. Managing Diversity
§ A single fixed ISA spec cannot work for all domains
§ So RISC-V designed to be modular:
- bases (RV32E, RV32I, RV64I, RV128…)
- standard extensions (MAFDQC, Zfh, Z… )
- custom extensions (Xaiwidget, X… )
§ Can combine modules to build application-specific ISA
§ But difficult to have broad support across software
and toolchain ecosystem for any combination
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9. Focusing Community Development
§ Many good ideas, task groups started, but need to
prioritize/finish extensions to make RISC-V successful
§ Technical Steering Committee to focus short-term
effort on meeting needs of a few application domains
- Where are RISC-V ISA gaps?
- Where are RISC-V ISA opportunities?
- What is needed for complete and compelling solution?
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10. Architecture Profiles
§ Initially (under development):
- RVA19 – application processor profile for 2019
- RVM19 – microcontroller processor profile for 2019
§ Only includes ratified extensions at date of creation
§ Specifies mandatory base/extensions, optional standard
extensions, and unsupported standard extensions
§ Reduces complexity for software ecosystem and RISC-V users
§ TSC to drive future roadmap for architecture profiles
§ Next target is RVA21 and RVM21 for December ‘21 Summit
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11. Profiles versus Platforms
§ Architecture profiles standardize ISA components
visible to software, both unprivileged and privileged
components
§ Platform standards standardize hardware
implementation choices including supported ISA,
booting, memory configurations, discovery, device
handling, debug attach, …

12. Vertical Industry Focus to follow
§ Architecture profiles provide generic design for class
of processor
§ Certain industry areas will require additional
specialized support (e.g., FUSA) to be prioritized by
TSC based on member interests
§ Enhance profiles, or add more profiles, for industry
verticals

13. Next Ten Years Summary
§ New application areas, and new demands for security
and dependability
§ Free and open, simple and modular ISA best way of
meeting these challenges
§ RISC-V International organizing to manage upcoming
complexity as RISC-V spreads to ever more
application areas, and ever more members and
contributors
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