The classification of MCU
    There are various classification methods for MCUS, among which the common ones include bit classification, architecture classification, application scenario classification, and memory type classification.
    In terms of bit classification, MCUS can be divided into 8-bit, 16-bit and 32-bit. 8-bit MCUS are suitable for simple control tasks with limited resources and are ideal for low-power and low-cost application scenarios, such as Atmel's AVR series and Microchip's PIC series. 16-bit MCUS are suitable for medium-complexity applications, offering higher performance and memory capacity, such as TI's MSP430 series. 32-bit MCUS have more powerful performance, faster processing speed and richer resources. They are often used in fields such as smart devices, automotive electronics and the Internet of Things, such as the ARM Cortex-M series and the STM32 series.
    Architecturally, MCUS can be divided into CISC architecture and RISC architecture. The instruction set of the CISC architecture is complex, and each instruction can perform more operations. It is suitable for small embedded systems, such as 8051 and PIC series. In contrast, the instruction set of the RISC architecture is streamlined, with fast execution speed and low power consumption, such as the ARM Cortex-M series and RISC-V.
    In addition, depending on the application scenarios, MCUS can be classified into general-purpose MCUS and dedicated MCUS. General-purpose MCUS are suitable for a wide range of application fields, such as home appliances, smart devices and industrial control, etc. Representative products include ST's STM32 series and NXP's Kinetis series. Specialized MCUS, on the other hand, are designed for specific industries or devices and integrate specific functional modules, such as automotive electronic MCUS, Bluetooth MCUS, and Wi-Fi MCUS, such as the Infineon and NXP S32 series of automotive MCUS, and the ESP32 series of the Internet of Things.
    Finally, in terms of memory types, MCUS can be classified into embedded storage MCUS and external storage MCUS. Embedded storage MCUS integrate ROM or flash memory internally for storing programs and are suitable for most embedded systems. External storage MCUS, on the other hand, do not integrate memory. Programs are stored in external memory, making them suitable for applications that require large-capacity program storage.