STMicroelectronics launches new STM32H7 series with 550 MHz

STMicroelectronics has launched the STM32H723, STM32H733, STM32H725, STM32H735 and STM32H730 series. The first STM32H7 series running at 550 MHz is also the first to integrate a 12-bit analog-to-digital converter with a 5M sampling rate. The first to have a 64kb L1 cache (32kb for data and instructions respectively). Despite the significant performance improvement, the size is still small. The new products can score up to 2778 CoreMark, or 1177 DMIPS. However, with up to 1MB of flash and 564KB of RAM, their memory configuration is in the middle of the product portfolio. The reason is that the new STM32H7s are aimed at industrial automation and have higher performance with a controlled chip area.

Support graphics processing

As we expected, the rise of graphical user interfaces marked the beginning of a new decade. Industrial applications increasingly rely on larger displays, richer graphics, smoother animations, and more complex layouts. As a result, engineers face a new challenge as they must do more within the same size and funding constraints. BOM costs cannot skyrocket, and PCBs are also more limited. Therefore, adding large amounts of memory is out of the question. Faced with competition, engineers took an unorthodox approach. Traditionally, manufacturers indiscriminately increase all specifications and hope for the best. The STM32H723, STM32H733, STM32H725, STM32H735, and STM32H730 take a different strategy. Our team customized their architecture to meet the specific needs of recent industrial applications.

2 development boards: STM32H735G-DK and NUCLEO-H723ZG

The best way to show new devices is to test them directly after powering on. Therefore, the best way to convince engineers of new products, technologies and applications is to use development boards directly. Therefore, STMicroelectronics released the STM32H735G-DK development board. The STM32H7x5 and STM32H730A/I include LDO and SMPS, while the STM32H7x3 and STM32H730V/Z only have LDO. In addition, unlike the STM32H73x, the STM32H735G-DK comes with an encryption core, so the STM32H735G-DK includes all the features required for all new stm32h7. In addition, the Nucleo-H723ZG simplified development board was also released, hoping to perform rapid prototyping around the STM32H723.

Now that the engineers have a demonstration platform, their next step is to decide what to show them more of the hierarchy. Therefore, we will list three potential applications that will help explain the special architecture of the new device. We will cover richer UI, predictive maintenance, and security.

No external memory required for richer GUIs

Let's take a conventional 2.2" display with a resolution of 320 x 240 (QVGA). After all, it is a typical screen in many industrial applications. Assuming a color depth of 24 bits per pixel, we can estimate the frame buffer to be around 1843200 bits or 230kb. Thus, we see that the memory configurations of the STM32H723, STM32H733, STM32H725, STM32H735, and STM32H730 can all be driven quickly without the need for additional RAM. Engineers can also choose to reduce the color depth to drive larger displays. For example, using 8 bits per pixel can support a 4.3" screen. In addition, the new devices can provide better animations and smoother transitions due to the increased frequency. For example, the new MCUs can better display content created in TouchGFX Designer while keeping costs under control.

Using external memory to achieve differentiated GUI

Other engineers may still want to use external RAM, in which case they now have two new possibilities. They can use the STM32H730, which is part of the Value Line family and has only 128KB of Flash, so it is cheaper. Or developers can use the STM32H72x or other STM32H73x to keep some code in the MCU for performance or security purposes. For example, engineers who want to drive a 7-inch display will most likely use external RAM. However, they can choose the STM32H723, STM32H733, STM32H725 or STM32H735 to keep part of the graphics framework in the embedded Flash to ensure better frame rates. Users can also use internal memory to benefit from features such as secure firmware installation or security module installation.

The new devices sit between the STM32H7A3/B3 and STM32H745/755. The former has more memory, but runs much slower and is more focused on low power. It targets applications that focus on graphical interfaces but don't need to consider computational throughput. On the other hand, the STM32H745/755 has more memory and a dual-core architecture that prioritizes performance. The STM32H723, STM32H733, STM32H725, STM32H735 and STM32H730 offer different compromises. They have the best single-threaded performance of all the STM32H7 series products, but their RAM and flash keep the BOM low.

Better ADC

Because ADCs are faster, more accurate predictive maintenance can be achieved.

Factory and home automation require applications to process large amounts of data, for example, vibration monitoring can be used to rely on predictive maintenance. However, unless the sensor data is large enough, the system cannot draw correct conclusions. Therefore, to solve this problem, the STM32H723, STM32H733, STM32H725, STM32H735 and STM32H730 all integrate a 12-bit ADC. It can receive 5 million samples per second, which can guarantee fast control or fast Fourier transform, etc. In addition, the fast 16-bit ADC on other STM32H7 series is still present on these new devices. In addition, thanks to its operating temperature of 140ºC and surface temperature of 125ºC, ST can guarantee the performance level under the harshest conditions. Similarly, the new devices have error code correction mechanisms on all Flash and RAM to provide a more robust architecture.

Instant decryption for greater security

Security is another key aspect of industrial applications, and the need for external memory can complicate things. Embedded memory is much less secure and vulnerable to data storage. Therefore, it is necessary to help developers protect data or code stored on external Flash. Therefore, the STM32H733, STM32H735 and STM32H730 (those with encryption cores) support on-the-fly decryption (OTFDec). Previously, the STM32H7A and STM32H7B supported OTFDec. With this new MCU, engineers can provide more security without having to consider performance losses. In addition, the new devices integrate two OctoSPI interfaces to connect to external Flash and external RAM.