The Value of the Arm Architecture

Contents

• This guide is designed to show benefits of working with Arm based technology
• The intended audience is SiPs and OEMs

Arm and Our Partners

Transforming the way people live and businesses operate
• Arm and its global ecosystem of technology
innovators empower the world’s most
successful business and consumer brands,
powering mobile, IoT, automotive and more
• Arm and our partners are driving growth
towards a world of a trillion connected devices
• Arm has a partnership-based culture and
business model, driving innovation wherever
compute is happening from the device to the
cloud

The Architects of Global Possibilities

Fuelling our partners innovation

Arm is Committed to Open Source Innovation

Open Collaboration with Governance

What do we Mean by “Fragmentation”

• Instruction set compatibility allows portability and reuse of code

• So long as the processors implement the same instruction set
– i.e. code written for Armv8-M processors is portable between different implementations of that instruction set
– CMSIS libraries improve abstraction across peripherals, RTOS etc

• RISC-V implementations encompasses many variations of the base ISA

• From floating point to atomics to multiplication to SIMD, vector and hypervisor as standard extensions
plus potentially many individual custom extensions
• Only the base instruction set is formally ratified
• Andes latest DSP extensions are incompatible with RISC-V ‘P’ specification

• Incompatibilities may require recompilation of code, or even different toolchains

• GCC for PULP family (including NXP VEGA) is incompatible with SiFive, SweRV, Rocket cores, despite all
being RISC-V implementations

From RISC-V ISA to a Fragmented Ecosystem

What Fragmentation Means

Supporting multiple forks is expensive and supporting all of them may not be possible

The Arm Ecosystem – Reducing Development Cost

CMSIS - Cortex Microcontroller Software Interface Standard

CMSIS enables consistent device support and simple software interfaces to the processor
and its peripherals, simplifying software reuse, reducing the learning curve for
microcontroller developers, and reducing the time to market for new devices.

Benchmarks Don’t Tell the Full Story

The wider picture

• Ease of development, availability of tools and
software libraries
• Does it reflect your application accurately?
• Is the score from a processor configuration you
will actually use?

Features that matter, but may not be in a

benchmark score

• Context switching, interrupt latencies, MPU
configuration
• Small MCU benchmarks such as Coremark and
Dhrystone won’t measure system performance
on a complex Cortex-A SoC
• Code size may be more important than
performance
• Only a few benchmarks consider energy
efficiency – eg EEMBC ULPMark
https://www.eembc.org/ulpmark/

Arm’s Vision for IoT Security

A holistic approach from design to product
https://www.arm.com/why-arm/architecture/platform-security-architecture/

Recent Industry Observations

https://semiengineering.com/open-source-processors-fact-or-fiction/

• “When you buy a core from the likes of an Arm, you know it is going to be an Arm
and you know it is going to work… The amount of verification that has to be done in
the average SoC project is probably 10X if they use an open ISA compared to buying
a standard off-the-shelf part.” Simon Davidmann, chief executive officer for Imperas
• “With open source, there is a danger of hardware Trojans or unintended behavior
sneaking into the design.” - Raik Brinkmann, president and CEO for OneSpin solutions
• “A standard, robust golden test suite to make sure your RISC-V implementation is
compliant does not exist yet,” Jerry Ardizzone, VP of worldwide sales for Codasip
• “It may run the compliance suite, but that does not mean it is a fully verified core,” -
Neil Hand, director of marketing at Mentor, a Siemens Business

Conclusion

Scalable solutions

• Arm’s architecture scales
with your product line,
allowing you to re-use your
software.
• Fastest time to market
• Lowest total cost of
ownership (reduced
software development time)
• Choice and availability of
tools, libraries, software,
developers, documentation,
support, etc.

Many choices available

• Arm’s mature ecosystem
consists of many choices for
silicon, tools, software, and
models that are proven and
prolific
• Arm has a strong
commitment to open source
with over 500 software
engineers regularly
contributing, with Arm and
Linaro being in the top 3
contributors to the Linux
kernel

Lowest risk

• Arm has a proven history in
the marketplace shipping
over 138Bn units.
• Arm is the low risk solution
• The Arm instruction set is
governed, evolving over time
to continue to meet the
needs of industry while
recognizing the value in not
allowing arbitrary extensions