Built around Arm’s Cortex-M33 core on a 40nm process, the devices have a new mode (low-power background autonomous – LPBAM – mode) that lets direct memory access and key peripherals operate without CPU intervention, allowing operation down to 19µA/MHz. There is also an integrated dc-dc converter.
STM32CubeU5 ‘enablement ecosystem’ is available from st.com and GitHub, and has more than 200 project examples and software for features like LPBAM, Wi-Fi, and Bluetooth Low-Energy.
“Support for OpenBootloader eases implementation of custom bootloader code,” said ST. “Azure RTOS with ThreadX RTOS as well as FreeRTOS and CMSIS OS wrappers ease industry certifications.”
The X-CUBE-STL self-test library and functional safety documentation are available to assist with safety-critical application development and IEC61508 SIL certification.
“There are also software packages that simplify cybersecurity and help comply with industry best practices,” according to the company. “These include reference code for secure boot and secure firmware update, and a trusted firmware example that leverages Arm’s TrustZone isolation within the core to implement secure services for PSA level 3 and SESIP level 3 certifications.”
X-CUBE-CRYPTOLIB cryptographic library has been updated with simplified API and extra cryptographic algorithms, and support for secure firmware install.
Hardware kits include the Discovery kit for IoT node (B-U585I-IOT02A, pictured), which contains MEMS context sensing and BLE and Wi-Fi modules. The board can connect directly to cloud services including Microsoft’s and Amazon’s.
There are so far two MCUs, STM32U575 and STM32U585 MCUs, with up to 2Mbyte of flash. Up to 500kbyte of the flash is long life (up to 100,000 read/write cycles) for storing user data.
ST has a blog about STM32U5 software and hardware here