STM32C071 is not simple, with up to 128KB flash memory and 24KB RAM, so that the graphics display system costing only $5 can also have a smooth GUI!

Latest update time：2024-09-20

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STM32C0 introduces a new product line - STM32C071, which has up to 128 KB of flash memory and 24 KB of RAM. It can drive a small 320 x 240 graphics display system through the SPI interface, providing a cost-effective solution for small appliances and white appliances.

STM32C071 series memory upgrades significantly to meet the large flash memory requirements of entry-level applications

The latest STM32C0 sub-product line, the STM32C071, has a significant memory upgrade, with up to 128 KB Flash and 24KB RAM; compared to the earlier STM32C031, the memory configuration has increased fourfold. Application scenarios that previously had to use higher-performance microcontrollers due to memory limitations now have the STM32C071 entry-level MCU option, making the product more competitive. This type of application is mostly powered by USB, and the STM32C071 adds a crystal-free USB controller. In addition, the STM32C071's internal clock can reduce the system's need for an external crystal oscillator, thereby reducing BOM costs and the complexity of PCB board layout.

Although the STM32C071 integrates larger flash memory and RAM, it still provides the same TSSOP20 package (6.5 mm x 4.4 mm) as the already available STM32C0. This package is very suitable for space-constrained USB external applications, where large flash memory and small package allow more complex applications to be implemented in such scenarios.

STM32C071 makes GUI more popular

Typically, the cost of a graphic display system based on STM32C071 includes a 2.4 TFT display without touch function, STM32C071, 4MB external flash memory, and a 2-layer PCB design, with a BOM cost of about $5. Such BOM cost and chip performance allow more embedded systems to afford GUI. For example, many small home appliances that use buttons or digital tubes for display can be upgraded to graphic display systems to highlight product advantages.

Taking the rice cooker UI as an example, the code developed based on the TouchGFX software tool is only 102KB, while part of the frame buffer and UI framework require 20.8KB of RAM. The GUI application requires about 900KB of external flash memory, and the SPI interface of the STM32C071 provides enough bandwidth to prevent the screen from freezing.

When developers are selecting products, if they need a reduced-dimensional product of STM32G0, STM32C071 is a very good choice. It bridges the performance gap between other STM32C0 series and STM32G0, has a USB controller, newly added SPI and I2C interfaces, and a 32-bit timer, and can achieve more functions compared to STM32C011 and STM32C031 sub-product lines. STM32C071 adds a 64-pin package, and all packages are fully compatible with STM32G0 pins.

▲ STM32C071 functional diagram

Start creating entry-level applications with STM32C0

Although 8-bit MCUs still have a certain market share, in most cases, the ultimate reason for choosing 8-bit MCUs is price. Developers choose 8-bit MCUs to reduce BOM costs, but behind the appearance of reducing costs, they ignore the high potential costs of the 8-bit architecture in the later stage, which means that the scalability is extremely limited .

During the MCU selection phase, developers will calculate the memory, computing throughput, pins, etc. required by the target system. If an 8-bit MCU is selected, the possibility of subsequent upgrades is almost zero; the inherent limitations of 8-bit MCUs also mean that developers must perform qualification certification on multiple devices, which often prolongs the time to market and misses market opportunities. At the same time, the embedded application market is moving from 8-bit to 32-bit MCUs in an irreversible iteration. Under such market conditions, if 8-bit MCUs are still used, then when the software stack and existing code are upgraded to 32-bit, they cannot be reused and need to be redeveloped.

Therefore, it is a wise choice for developers to start creating entry-level applications with the new 32-bit MCU STM32C0 from now on. As a new microcontroller for entry-level applications, the STM32C0 series is as cheap as an 8-bit MCU. It is based on the Cortex-M0+ core, has a main frequency of 48 MHz, and a CoreMark score of 114 points. Its performance in all aspects far exceeds that of an 8-bit MCU. The STM32 software and hardware ecosystem is fully compatible with the STM32C0, which will bring great convenience to developers.

To help engineers upgrade their systems from 8-bit MCUs to 32-bit MCUs as efficiently as possible, ST has released an application note for migrating from STM8L or STM8S to STM32C0 . This document not only explains in detail the peripheral migration method, but also shows that in most cases, migrating from 8-bit to 32-bit architecture usually means that the code size only increases by 6% to 15%. STM32's software development environment, such as software tools such as STM32CubeMX and STM32CubeIDE , debugging software such as STM32CubeProgrammer , or STM32Cube expansion packages , will greatly optimize the workflow, allowing for easy reuse of code or modules to speed up development.

In addition, it is worth mentioning that if developers choose STM32C0, when the product performance needs to be upgraded, they can quickly migrate to STM32G0. The two have the same Vdd and Vss power supplies, similar ADC, timer and high-speed RC oscillator, and are fully pin-compatible, without the need to add external components.

STM32C0 product line

In the near future, the STM32C0 series will also release the STM32C051, STM32C091 and STM32C092 sub-product lines.

The STM32C051 has twice the memory of the STM32C031, namely 64KB of flash memory and 12KB of RAM, providing developers with more options.

The STM32C091 and STM32C092 are almost identical, with up to 256KB of flash memory, two I2C and two SPI buses, four USART interfaces, and a 12-bit ADC with up to 19 channels, as well as more general-purpose timers than other models to support more complex applications. The main difference between the two is that the STM32C092 has an FDCAN controller and 30KB of RAM; while the STM32C091 does not have this controller, its RAM is 36KB.

Rewarded Interaction

Let's start with NUCLEO-C071RB to learn about the performance of STM32C071 products. If you have a development project for upgrading 8-bit to 32-bit MCU, please share it in the comment area. We will select 10 fans and give each of them a NUCLEO-C071RB development board.

Event time : From now until September 30;

Kind tips:

1. This activity is limited to practitioners in the electronics and related industries and college students in related majors;

2. Any cheating behavior will result in disqualification from the event;

3. The list of winners will be posted at the top of the list.