STM32 has always been one of the focal points of attention for everyone. Hence, catering to your interests, I’m here to present an introduction to STM32. Check out the details below:
I. STM32
The STM32 Connectivity series microcontrollers introduce a full-speed USB (OTG) interface, enabling terminal products to function as both USB hosts and peripherals when connected to other USB devices. This series also incorporates Ethernet interfaces with hardware support for IEEE1588 Precision Time Protocol (PTP). Implementing this protocol in hardware reduces CPU overhead, enhancing real-time applications and synchronization in networked devices.
The new Connectivity series is the first STM32 family product to integrate two CAN2.0B controllers, enabling developers to create gateway devices connecting two industrial standard CAN (Controller Area Network) buses. Moreover, these microcontrollers simultaneously support Ethernet, USB OTG, and CAN2.0B peripheral interfaces, allowing developers to design gateway devices integrating all these peripheral interfaces with just one chip.
The STM32 Connectivity series enhances audio performance, employing an advanced phase-locked loop mechanism to achieve audio-grade I2S communication. Combined with USB host or peripheral functionality, STM32 can read, decode, and output audio signals from external storage (such as USB drives or MP3 players). Designers can also develop Human-Machine Interface (HMI) functions, like play and stop buttons, and display interfaces on these microcontrollers. This feature makes it suitable for various home audio devices like sound base systems, alarm/music players, and home theaters.
The new series integrates advanced connectivity peripherals, standard STM32 peripherals (including a PWM timer), a high-performance 32-bit ARM Cortex-M3 CPU, enabling developers to integrate various functionalities (such as motor control, user interface control, and device interconnectivity) into devices (like home appliances, building or industrial automation). Other target applications include systems requiring networking, data logging, or USB peripheral expansion, like patient monitoring, retail terminals, vending machines, and security systems.
The STM32 series of microcontrollers, including the new Connectivity series, comes with various associated software and development tools. These include the software library provided by STMicroelectronics free of charge, and extensive support from third-party tool manufacturers. STMicroelectronics is also set to launch a new evaluation board and is currently providing samples of the STM32F105 and STM32F107 Connectivity series to major clients.
II. STM32 FSMC (Flexible Static Memory Controller) Extension
FSMC adapts to various external memory types by emitting corresponding data/address/control signals to match signal speeds. This enables STM32 microcontrollers not only to apply various types and speeds of external static memory but also to simultaneously extend multiple types of static memory without adding external devices. This meets the comprehensive requirements of storage capacity, product volume, and cost in system design.
FSMC technology advantages include:
Supports multiple types of static memory. STM32, through FSMC, can be directly connected to SRAM, ROM, PSRAM, NOR Flash, and NAND Flash memory pins.
Supports rich storage operation methods. FSMC supports asynchronous read/write operations of various data widths and synchronous burst access modes for NOR/PSRAM/NAND memory.
Supports the simultaneous extension of multiple memories. Different BANKs in the FSMC’s mapped address space are independent and used to expand different types of memory. When multiple external memories are expanded and used in the system, FSMC prevents access conflicts between memories by setting bus idle delay parameters.
Supports a wider range of memory models. By setting FSMC’s timing parameters, the speed range of available memory in the system is expanded, offering users a flexible selection space for storage chips.
Allows code to run directly from the external storage expanded by FSMC without first loading into internal SRAM.
STM32 microcontrollers support access to NOR Flash and NAND Flash, two memory extensions with completely different access modes, because FSMC internally includes NOR Flash and NAND/PC Card controllers, supporting two completely different memory access modes. Inside the STM32, one end of the FSMC is connected to the Cortex-M3 core through the internal high-speed AHB bus, while the other end faces the external bus for extended memory. The core sends access signals for external memory to the AHB bus, which, through FSMC, converts them into signals compliant with the external memory communication protocol, delivering them to the respective pins of the external memory. FSMC acts as a bridge, converting signal types and adjusting signal widths and timings, shielding differences between different memory types, making no difference to the core.”
