Renesas Cortex-M MCU family adds security for IoT and a support ecosystem
Called the RA family, they are PSA Certified Level 1 and come in four series:
- RA2 Series – Cortex-M23 up to 60 MHz
- RA4 Series – Cortex-M4 up to 48MHz (or 100MHz, the firm has said both)
- RA6 Series – Cortex-M4 up to 120MHz (up to 200 MHz)
- RA8 Series – to be released later – Dual 200MHz cores
This looks a little like Renesas’ existing RS ‘Synergy’ family?
It does, agrees the Renesas marketing director Tim Burgess, but Synergy MCUs are qualified to be used with a closed qualified family of tools and hardware – together forming the ‘Synergy Platform’ – while 3rd party tools can be used with RA devices.
But is it the same silicon?
“We don’t want to disclose that,” Burgess told Electronics Weekly, adding: “There are a whole lot of new RA devices coming along that you won’t find similar to Synergy devices.”
For RA MCUs, Renesas has has assembled a partner ecosystem to deliver software and hardware to support them.
“The RA Family ‘flexible software package’ [FSP] provides an open architecture that allows customers to re-use their legacy code and combine it with software examples from Renesas and ecosystem partners to speed implementation of complex functions like connectivity and security,” according to Renesas. “The FSP features Amazon FreeRTOS and will also add out-of-box support for ThreadX RTOS and middleware on Cortex-M23 and Cortex-M33 MCUs by early 2020, offering a device-to-cloud option for developers. These out-of-box options can be easily replaced and expanded with any other RTOS or middleware.”
Initial line-up – RA8 and Cortex-M33 devices come later
32 RA MCUs are released today, in five groups, split amongst three series – in the language of Renesas.
They offer a choice of Cortex-M4 or Cortex-M23, package pin-counts from 32 to 176, between 256kbyte and 2Mbyte of flash, and from 32 to 640kbyte of RAM.
Connectivity options include USB, CAN, Ethernet and capacitive touch sensing.
In 2020, the roadmap predicts more advanced devices including dual-core RA8 parts and Cortex-M33 options.
“The roadmap offers PSA Certified and Trusted Firmware-M [TF-M] API compliant devices, including Cortex-M33 MCUs, low-power Cortex-M23 MCUs, and Bluetooth Low-Energy IEEE 802.15.4 wireless IoT products,” according to Renesas. “MCUs with TF-M / PSA certification will give customers the confidence and assurance to deploy secure IoT endpoint and edge devices, and smart factory equipment for Industry 4.0.”
Security is backed by versions of Renesas’ Secure Crypto Engine – with (7) or without (5) asymmetric capability. Secure Crypto Engine 9 – with resistance to side-channel attacks, will arrive next year
For IoT security, the firm has included versions of its Secure Crypto Engine (see chart) with NIST CAVP certifications on top of ‘Arm TrustZone for Armv8-M’ virtualisation.
This security block (depending on version) provides symmetric and asymmetric encryption and decryption, hash functions, true random number generation (TRNG), and key handling – the latter including key generation and MCU-unique key wrapping.
“An access management circuit shuts down the crypto engine if the correct access protocol is not followed, and dedicated RAM ensures that plain-text keys are never exposed to any CPU or peripheral bus,” said the firm.
To ease development, he RA family development environment offers on-chip debug, IDEs, compiler, support tools, board evaluation kits, design files, schematics, PCB layouts and BOM.