STLink

ST-Link is a family of in-circuit debugging and programming tools produced by STMicroelectronics for STM32 (and STM8) microcontrollers. It connects to a host PC via USB and to the target device through SWD (Serial Wire Debug) or JTAG interfaces, enabling programming, flashing, and debugging. ST-Link is commonly used with development environments such as STM32CubeIDE, Keil MDK, IAR, and OpenOCD, and can also be controlled via the ST-LINK Utility software for firmware upgrades and basic operations.

The ST-Link family includes several variants, notably ST-LINK/V2, ST-LINK/V2-1, and ST-LINK/V3, as well as compact forms like ST-LINK/V3MINI. ST-LINK/V2 is the long-standing version found on many evaluation boards, while ST-LINK/V3 offers higher performance, greater speed, and enhanced capabilities. Some boards also integrate the ST-LINK inside the board itself (for example, Nucleo boards), reducing the need for a separate probe. ST-LINK devices provide an on-board microcontroller that translates USB commands into target-debug actions and may expose a virtual COM port for UART communication with the target when available.

Typical capabilities include programming and erasing flash memory, mass erase, read and write memory, option bytes, and debugging actions such as setting breakpoints and stepping through code. ST-LINK tools can measure the target voltage, verify flash contents, and perform firmware updates for the ST-LINK firmware itself. They are designed to work with STM32 and STM8 devices and are supported by both vendor-provided and third-party debugging software, making them a standard choice for development and field diagnostics involving ST microcontrollers.