ST STLINK-V3MODS - STLINK-V3 MODS and STLINK-V3 MINI Functions; SWD with SWV; Jtag; Virtual COM Port (VCP)

UM2502 Rev 2 15/28
UM2502 STLINK-V3MODS and STLINK-V3MINI functional description
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5.5 STLINK-V3MODS and STLINK-V3MINI functions
All functions are designed for high performance: all signals are 3.3 V compatible. The
following description concerns STLINK-V3MODS and STLINK-V3MINI except for some
mentioned sections and indicates where to find the functions on the boards and connectors.
5.5.1 SWD with SWV
SWD protocol is a Debug/Program protocol used for STM32 microcontrollers with SWV as a
trace. The signals are 3.3
V compatible and may perform up to 24 MHz. This function is
available on CN2 (STLINK-V3MODS) and CN5 (STLINK-V3MINI).
5.5.2 JTAG
JTAG protocol is a Debug/Program protocol used for STM32 microcontrollers. The signals
are 3.3
V compatible and may perform up to 21 MHz. This function is available on CN2
(STLINK-V3MODS) and CN5 (STLINK-V3MINI).
5.5.3 Virtual COM port (VCP)
The serial interface VCP is directly available as a Virtual COM port of the PC, connected to
STLINK-V3MODS and STLINK-V3MINI USB connector CN5. This function may be used for
STM32 microcontrollers. The signals are 3.3
V compatible and may perform from 732 bps to
16
Mbps. This function is available on CN2 (STLINK-V3MODS) and CN5 (STLINK-V3MINI).
A second Virtual COM port may be activated on STLINK-V3MODS, as detailed later in
Section 5.5.5 (Bridge UART).
For details regarding baud rates, refer to section 14.2. of the user manual STLINK-V3SET
debugger/programmer for STM8 and STM32 (UM2448).
5.5.4 Mass storage interface
The STLINK-V3MODS and STLINK-V3MINI tiny probes implement a virtual mass storage
interface allowing the programming of an STM32 target Flash memory with drag-and-drop
action of a binary file from a file explorer. This ability requires the STLINK-V3MODS or
STLINK-V3MINI tiny probe to identify the connected target before enumerating it on the
USB host. As a consequence, this functionality is available only if the target is connected to
the STLINK-V3MODS or STLINK-V3MINI tiny probe when it powers up.
The mass storage interface may be disabled or enabled again by reprogramming the
ST-LINK firmware. This can be performed with the STLinkUpgrade application. Activate the
<change type> checkbox then select the firmware with or without mass storage and launch
the update. The action is reversible.
5.5.5 Bridge functions (STLINK-V3MODS only)
The STLINK-V3MODS tiny probe provides a proprietary USB interface allowing the
communication with an STM32 target with several protocols: SPI, I
2
C, CAN, UART and
GPIOs. This interface may be used to communicate with the target bootloader, but may also
be used for customized needs through its public software interface. All bridge signals are
accessible on CN2.