ST-LINK V3: STDC14 pin assignment with virtual COM port
With the ST-LINK V3, ST introduced the 14-pin 1.27 mm STDC14 connector. It carries SWD and JTAG plus a virtual COM port (VCP) — debugging and serial output over a single cable.
14-pin — TC2070 and ECV3-14
| Contact | STDC14 |
|---|---|
| 1 | NC (reserved by ST) |
| 2 | NC (reserved by ST) |
| 3 | T_VCC |
| 4 | T_SWDIO / TMS |
| 5 | GND |
| 6 | T_SWCLK / TCK |
| 7 | GND |
| 8 | T_SWO / TDO (optional) |
| 9 | T_JRCLK (optional) |
| 10 | T_JTDI (optional) |
| 11 | GNDDetect (optional) |
| 12 | T_NRST |
| 13 | T_VCP_RX (optional) |
| 14 | T_VCP_TX (optional) |
Plug-of-Nails™ TC2070 Series (example), view onto the PCB
Edge-Connect™ ECV3-14, view onto the PCB
Matching cables and adapters: TC2070-IDC-050 · TC2070-IDC-NL-050 · ECV3-14-2AP-IDC-050 · COLL-ARM20-14P-050
For your own layout
- A 14-contact Tag-Connect footprint (TC2070) and a cable wired 1:1 produce exactly this assignment — contact n on STDC14 pin n, provided the footprint follows the numbering scheme.
- The 6- and 10-pin STDC14 cables carry only part of the signals: SWD on 6 pins, SWD and JTAG on 10 pins, no VCP.
- The ST-LINK/V2 and older ST-LINKs have a 20-pin 2.54 mm connector, not STDC14.
The position of the contacts is shown in Connector numbering.
All tables are derived from the pin assignments of the individual cables and adapters — manufacturer information, datasheets and our own measurements. For a specific cable, the table on its product page is authoritative.
All assignments at a glance: Pin assignments · SWD · JTAG · UART · Other assignments