Bringing new levels of security for constrained IoT devices

It is only with semiconductor, systems and software companies adopting more secure technology will we see more secure devices entering the market. Microchip announced the first chip families available based on the Arm Cortex-M23 processor - the SAM L11 and the SAM L10 - with the SAM L11 based on TrustZone for Armv8-M, bringing a new level of trust and security to embedded systems.

Since this chip is based on the familiar Cortex-M programming model, security is now even more accessible for embedded software developers. This technology enables product manufacturers to ensure a trusted foundation at the core of their most constrained devices, bringing robust protection for the valuable data being collected by even the smallest IoT devices.

Where will we see the impact?
Appliances are rapidly adding more intelligence and being connected to the Internet. TrustZone technology enables software isolation on the Cortex-M23, delivering the required level of foundational security for even the smallest embedded and connected IoT devices and preventing malicious access.

The Microchip SAM L11 and SAM L10 chip families are widely applicable across automotive, appliance, medical and consumer applications.

Automotive applications in body control, for example door locks, can benefit from the security features built into the Cortex-M23. LIN is a popular bus used to control various body functions in automobiles, and TrustZone can help secure the bus to prevent unauthorised access to the vehicle.

Medical instruments, such as an EKG heart rate monitor that stores data over time, require compliance to various medical privacy standards. By using TrustZone in the SAM L11, only medical professionals can be authorised to access collected and stored patient data.

What was released by Microchip?
Microchip unveiled two MCU families - the SAM L11, featuring TrustZone for Armv8-M for applications that require embedded security, and SAM L10, for those applications where security is not a must-have, but where customers are still interested in low power and touch capabilities.

The new families boast a rich feature set, extremely low power consumption, and a new capacitive touch capability with 'best-in-class' water tolerance and noise immunity.

Feature Table: SAM  L11 and SAM  L10

Microchip SAM L11 Xplained Pro evaluation kit

A deeper dive into the SAM L11 and SAM L10 MCUs
Here’s a quick run-down of the key features of the new Microchip families:

• Robust security: The SAM L10 and SAM L11 include chip-level tamper resistance, secure boot and secure key storage that, when combined with TrustZone, establish a hardware root of trust. Together these protect customer applications from both remote and physical attacks.
• Capacitive touch capabilities: The Peripheral Touch Controller (PTC) allows designers to easily add touch interfaces that provide an impressively smooth and efficient user experience in the presence of moisture and noise while maintaining low power consumption
• picoPower technology: picoPower devices are designed from the ground up for the lowest possible power consumption with flexible clocking options, user-selectable performance levels and SleepWalking peripherals.
• Peripheral flexibility: The SAM L10 and SAM L11 offer an innovative serial communication module that is fully software-configurable to handle I2C, USART/UART, and SPI communications.

To top it all off, the new Microchip families feature the Arm Cortex-M23 processor. What does that bring?

The Cortex-M23 processor: Security, efficiency and ease of use
The Cortex-M23 is built for small, energy-sipping IoT and embedded products. It extends the capability of the smallest lowest power devices, providing security, enhanced efficiency, performance and scalability for deployment even in the most constrained contexts. The key benefits of the Cortex-M23 include:

A security foundation in the heart of your SoC
TrustZone technology is already deployed in billions of devices and is now accessible for Cortex-M in the Armv8-M architecture - with the same, proven, system-wide security concept, but optimised for embedded, deterministic devices.

The Cortex-M23 processor brings TrustZone security to even the smallest and lowest-powered devices, enabling programmers to use a familiar programming model to make software isolation more achievable. The processor supports the main recommendations from the Platform Security Architecture (PSA), which is a framework providing a common approach to security for both hardware and software. PSA offers a consistent foundation for designers and developers working on IoT and embedded devices. 

The PSA documentation and open source code (Trusted Firmware-M) is perfectly positioned for developers using CPUs like the Arm Cortex-M23 processor. 

System designers can differentiate their products by adding valuable software and algorithms for further functionality, with the knowledge that they are protected with TrustZone software isolation. Trusted execution is now achievable, even in the most constrained embedded devices.

Software isolation with TrustZone for Armv8-M

Longer battery life with an efficient Cortex-M processor
The Cortex-M23 processor allows developers to optimise power usage for specific applications with built-in, low power features. With its three highly optimised low power modes, the processor conserves energy to match processing demands. The Cortex-M23 is 75% smaller than the Cortex-M33 and 50% more efficient, running on even less energy for even longer.

The combination of the Cortex-M23 ultra-low power core, the ability of the SAML10/11 to operate down to 1.62V, and the low leakage processes and libraries together deliver industry-leading low power consumption in active and sleep modes.

The Cortex-M23 processor is the most efficient Cortex-M processor with TrustZone

Easier software development
Software developers can use their existing know-how of the Cortex-M programmer’s model when working with the Cortex-M23. Familiar development tools, such as Arm Keil MDK and Arm Compiler, all support the new processor too. And if using the ULINKplus debug adapter in conjunction with Keil MDK, developers can also optimise for power consumption, making their device energy-efficient, both in terms of hardware and software.

By accessing the broad Arm ecosystem, developers can choose from a wide selection of ecosystem partners offering software, tools, compiler, RTOS and security solutions. There are also a wealth of resources and documentation, along with Q&A support, at the TrustZone Community for Armv8-M.

So, why wait? Start developing your embedded device
With the advance of the IoT, security is no longer an option; embedded developers and device manufacturers must take it seriously. And now, security is no longer for specialists - through the Cortex-M23 based Microchip devices, developers can access the technology needed to build a secure foundation in the heart of their device.