STMicroelectronics’ STM32 MCU layout currently includes 5 product series: mainstream MCU series, ultra-low power consumption series, high-performance series, wireless series and MPU. In terms of seniority, the ultra-low-power series is the second oldest product series, only inferior to the mainstream MCU series.

From the STM32L1 released in 2009 to the STM32L0, STM32L4, STM32L4+, and STM32L5 released in succession, STMicroelectronics’ ultra-low power consumption product line has been deducing the chapter of the perfect combination of ultra-low power consumption and product performance.

A few days ago, the product line released the latest product series – STM32U5. From the introductions of Cao Jindong, Marketing and Application Director of the Microcontroller Division of STMicroelectronics China, and Peng Zunian, Marketing Manager of Microcontroller Products of STMicroelectronics China, it is not difficult to see that the identity of the STM32U5 is extraordinary, the comprehensive upgrade of the core and process, The positioning of the new ultra-low power consumption flagship, strong performance and rich configuration, all show that STM32U5 will be a new generation star product of STMicroelectronics ultra-low power series.

STM32U5 can be said to be a combination of many auras: the first ultra-low power STM32 based on 40 nm process; the first STM32 MCU to pass Level 3 certification; 535 ULPMark-CP low power performance; 240DMIPS/651 Coremark performance scores .

“The perfect combination of low power consumption and high performance”, “have both the fish and bear’s paw”, such language is often used to describe the previous STM32 ultra-low power consumption products. Since the release of the STM32L5 based on Cortex-M33, especially to the STM32U5, it may be more suitable to use a tripartite. Low power consumption, high performance and safety, these three excellent performances are like three legs, firmly supporting the new flagship of STM32 ultra-low power consumption MCU.

Compared with the previous products, the low power consumption performance of STM32U5 is further improved, the product performance is more powerful, and the security is another surprise that STM32U5 brings to users. The products of these users may be smart flow meters, wearables, medical monitoring equipment, or POS payment terminals…

Cao Jindong, Marketing and Application Director, Microcontroller Division, STMicroelectronics China

Peng Zunian, Microcontroller Product Marketing Manager, STMicroelectronics China

LPBAM brings better system power consumption characteristics

To measure the new flagship of the low-power series, the first to bear the brunt is the low-power performance. STM32U5 handed in a dazzling transcript. The following figure shows the test results of the third-party EEMBC ULP Benchmark. This test result not only includes the performance evaluation in the running state, but also comprehensively reflects the power consumption level of the chip in various modes. According to Peng Zunian, many users may pay more attention to parameters such as µA/MHz of ultra-low power consumption products, but this parameter does not represent the overall performance of a system in the running state and the evaluation of CPU power consumption in specific scenarios. consumption level. ULP Benchmark will comprehensively evaluate the system’s operating performance, operating power consumption, sleep state and power consumption when waking up for different test conditions. In some of the tested items, an evaluation of the power consumption of the chip peripherals is also included.

Excellent low power performance comes from innovative design. STM32U5 has a special feature called Low Power Background Autonomous Mode (LPBAM, Low Power Background Autonomous Mode). Peng Zunian introduced that usually when the chip enters a low power consumption mode, the CPU needs to be powered off, but there may be many sensors on the outside of the product. The data of these sensors may be input to the main control chip in real time. Usually, the data transmission of this sensor requires the system or CPU to perform some operations and do some data processing work, but in the STM32U5 product On the MCU, a unique peripheral is set up, which can transfer the data on many common interfaces, including I2C, SPI, serial port, ADC and other peripherals, to a SRAM4 inside the microcontroller without waking up the CPU, which is about 16kB. When the data accumulates to a certain amount, wake up the Cortex-M33 core for one-time batch processing. Through this unique design, for models similar to classic data acquisition and wake-up processing, the number of CPU wake-ups can be reduced to 1/10 of the original.

In addition, the STM32U5 also applies many advanced and flexible low-power designs, providing more power modes and more power-saving tips for user designs.

Excellent performance and rich on-chip resources

As the first ultra-low power STM32 MCU based on 40 nm process, the main frequency of STM32U5 has been increased from 110 MHz to 160 MHz compared with the previous generation product STM32L5, and the performance has also been greatly improved. The STM32U5 series has reached a performance score of 240DMIPS and 651Coremark. At the same time, in order to further tap the potential of chip performance, STMicroelectronics also designed units such as mathematical operation accelerators and ART accelerators on the STM32U5 to assist and accelerate the efficiency of the entire chip’s internal computing system.

STM32U5 is currently the flagship product of the ultra-low power consumption series, and the Flash configuration is more sufficient and richer than the previous generation products to meet user needs. The STM32U5 series will cover the Flash range from 128 KB to 4 MB. The first members of the STM32U5 family, STM32U575 and STM32U585, which have been released so far, basically cover the space required for Flash from more than 512 KB to 2 MB. In the future, a larger-capacity version of the STM32U5 series, as well as a smaller and more streamlined low-cost STM32U5, will be launched.

In addition, the STM32U5 family offers advanced high-speed 14-bit analog-to-digital converters (ADCs) for next-generation sensing and tracking applications. And use the multi-function digital filter (MDF) and audio digital filter (ADF) to replace ST’s proven Sigma-Delta modulation digital filter (DFSDM). Greatly improved voice detection capabilities, which enable users to integrate AI into low-cost, low-power microcontroller-based application scenarios by improving voice activity detection performance.

Two-pronged approach: information security + functional safety

With the increasing intelligence and networking requirements of embedded devices, industrial devices and personal consumer electronics, security has become an increasingly important feature of MCUs. Security is an important consideration for STM32U5.

Peng Zunian introduced that in terms of security, STM32U5 has designed layers of protection. First of all, it is based on the Cortex-M33 core, which inherently supports the isolation architecture such as TrustZone, but on the STM32U5, the isolation of a single core or the support of TrustZone is not enough. STMicroelectronics has designed an isolated configuration for storage, busses and peripherals within the product. In addition to isolation, STM32U5 also adds more security encryption functions, as well as a fully controllable multi-layer protection state machine. In terms of storage protection, a new update has also been made. For the anti-tampering of internal storage, space such as OTP has been added, and there are more active anti-violation active tamper designs. Under such a complete security design, the Secure Boot secure boot of STM32U5 can also allow users to obtain an immutable and stable root of trust in their security architecture design. Finally, STM32U5 passed PSA Level3 certification. This is also the first product among all STM32 products that can pass the three-level safety certification.

Realizing ultra-high performance on ultra-low-power MCUs, coupled with powerful security functions, STMicroelectronics once again interprets the new height of ultra-low-power MCUs with STM32U5. Innovation has always been a core element of this. As Director Cao Jindong said: “ST released the first STM32 in 2007 and up to now, we have been adhering to the slogan of ‘unleash your creativity’ to drive the release of our products. In this creative way, we have a good relationship with our users. Various forms of communication. We hope that this innovation will not only be reflected in ST’s own product design, but also in helping customers make innovative designs.”