Renesas Develops Technologies for Automotive Communication Gateway SoCs

Renesas Electronics Corporation (TSE: 6723), a premier supplier of advanced
semiconductor solutions, today announced that it has developed four
technologies for system-on-chip (SoC) devices for in-vehicle communication
gateways. These SoCs are expected to play a crucial role in defining the
next-generation electrical/electronic (E/E) architecture in automotive
systems.

SoCs for automotive gateways must provide both high performance to implement
new applications such as cloud services, and low power consumption when they
are not in use. They also need to deliver fast CAN response to support
instant start-up. Additionally, these SoCs need to provide power-efficient
communication technology that enables network functions as a gateway using
limited power and security technology to enable safe communication outside
the vehicle. To meet these requirements, Renesas has developed (1) an
architecture that dynamically changes the circuit operation timing to match
the vehicle conditions with optimized performance and power consumption, (2)
fast start-up technology by partitioning and powering essential programs
only, (3) a network accelerator that achieves a power efficiency of 10
gigabits per second/watt (Gbps/W), and (4) security technology that prevents
communication interference by recognizing and protecting vital in-vehicle
communication related to vehicle control.

Renesas announced these achievements at the International Solid-State
Circuits Conference 2023 (ISSCC 2023), February 19 – 23 in San Francisco,
California.

Details of the new technologies include:

1. Architecture that optimizes processing performance and power consumption
depending on vehicle conditions

Communication gateway SoCs need to deliver processing performance exceeding
30,000 Dhrystone million instructions per second (DMIPS) when running, while
also keeping standby power consumption to 2 mW or less in order to maintain
battery life. Typically, high-performance SoCs also have high power
consumption in standby mode, while low-power SoCs with small standby power
consumption have performance issues. To resolve this tradeoff, Renesas
combined in a single chip a high-performance application system and a
control system optimized for ultralow standby power consumption. The new
architecture controls the power supplies of these two subsystems and changes
the timing of circuit operation to achieve an optimal balance between
performance and power efficiency. This results in higher performance during
operation and lower power consumption during standby.

2. Fast start-up technology with external flash memory achieving the same
fast speed as embedded flash memory

Since communication gateway SoCs manage processing of critical functions
related to vehicle control, they must be able to respond to CAN within 50
milliseconds (msec.) of start-up. However, if the SoC uses a process that
does not support embedded flash memory, the start-up program must be
encrypted and stored in external flash memory. This means that it takes
additional time to load program data and decrypt it. To solve this issue,
Renesas developed technology that splits the program into sections and
initially loads and decrypts only an essential portion for start-up, while
continuing to load the rest of the program in parallel. This enables a fast
response to CAN (50ms or less), even when using external flash memory.

3. Highly efficient network accelerator with 10 Gbps/W communication
efficiency

To allow air cooling and heat dissipation for electronic control units
(ECUs), communication gateway SoCs must keep power consumption to 7 watts or
less. Since computing processing performance of 30,000 DMIPS or higher
requires approximately 6 watts of power, only around 1 watt can be used for
network processing. This presents a challenge as the total communication of
10 Gbps must be achieved using 1 watt of power, with a processing efficiency
of only around 3Gbps/W when processed by the CPU. To work around this issue,
Renesas offloaded processing from the CPU to a custom network accelerator,
achieving higher efficiency at 9.4 Gbps/W. Additionally, Renesas boosted
efficiency to 11.5 Gbps/W by switching the routing method from a
conventional TCAM approach to a hash table in SRAM.

4. Security technology to prevent interference with communication requiring
high reliability

A communication gateway SoC performs a mixed set of tasks such as data
processing related to vehicle control that requires a high level of
reliability, and large amounts of random data communication with cloud
services and others. Since vehicle control is essential to ensuring safety,
protecting and separating mission-critical data is important. However,
despite the differences in data types, all data is transmitted through the
same in-vehicle network, leading to physical intersections and raising
security issues. To address this challenge, Renesas developed security
technology that analyzes incoming packets to the SoC. It determines whether
or not they contain essential data, and assigns them to different pathways
and control functions within the network accelerator. This prevents
interference with data that requires high reliability and safeguards
in-vehicle data communication from a variety of security threats.

These four technologies have been incorporated into Renesas’ R-Car S4
vehicle communication gateway SoC. With the latest R-Car S4, developers can
accelerate advances in E/E architectures, implement secure connection with
cloud services, and ensure safe and reliable vehicle control at the same
time.

About Renesas Electronics Corporation

Renesas Electronics Corporation (TSE: 6723) empowers a safer, smarter and
more sustainable future where technology helps make our lives easier. A
leading global provider of microcontrollers, Renesas combines our expertise
in embedded processing, analog, power and connectivity to deliver complete
semiconductor solutions. These Winning Combinations accelerate time to
market for automotive, industrial, infrastructure and IoT applications,
enabling billions of connected, intelligent devices that enhance the way
people work and live. Learn more at renesas.com.