SWD pin assignment of the Tag-Connect footprints
Serial Wire Debug (SWD) is the two-wire debug interface of ARM Cortex microcontrollers: SWDIO and SWCLK, plus supply, ground and usually reset. SWO carries trace output and is optional.
6-pin — TC2030 and ECV3-06
| Contact | SWD |
|---|---|
| 1 | VCC |
| 2 | SWDIO |
| 3 | nRESET |
| 4 | SWCLK |
| 5 | GND |
| 6 | SWO (optional) |
Plug-of-Nails™ TC2030 Series (example), view onto the PCB
Edge-Connect™ ECV3-06, view onto the PCB
Matching cables and adapters: TC2030-CTX · TC2030-CTX-NL · TC2030-CTX-20 · TC2030-CTX-20-NL · TC2030-CTX-NL-LEMTA · TC2030-CTX-STDC14 · TC2030-CTX-NL-STDC14 · ECV3-06-CTX · ECV3-06-CTX-STDC14 · ARM20-CTX · COLL-ARM20-06-IDC · COLL-ARM20-MALE-06-IDC
10-pin — TC2050 and ECV3-10
| Contact | SWD |
|---|---|
| 1 | VCC |
| 2 | SWDIO |
| 3 | GND |
| 4 | SWCLK |
| 5 | GND, optional +5 V |
| 6 | SWO (optional) |
| 7 | — |
| 8 | — |
| 9 | GND / GNDDetect (optional) |
| 10 | nRESET |
Plug-of-Nails™ TC2050 Series (example), view onto the PCB
Edge-Connect™ ECV3-10, view onto the PCB
Matching cables and adapters: TC2050-ARM2010 · COLL-ARM20-10-IDC · ECV3-10-IDC-050-20 · ECV3-10-IDC-STDC14 · TC2050-IDC-NL-050-STDC14
14-pin — TC2070 and ECV3-14
| Contact | SWD (STDC14) |
|---|---|
| 1 | — |
| 2 | — |
| 3 | T_VCC |
| 4 | T_SWDIO |
| 5 | GND |
| 6 | T_SWCLK |
| 7 | GND |
| 8 | T_SWO (optional) |
| 9 | — |
| 10 | — |
| 11 | GNDDetect (optional) |
| 12 | T_NRST |
| 13 | — |
| 14 | — |
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
- Minimum: VCC, SWDIO, SWCLK, GND. VCC is the reference voltage for the debugger, not its supply.
- nRESET is strongly recommended — without it, controllers that have reconfigured their SWD pins often cannot be connected again.
- On 6, 10 and 14 pins, SWDIO and SWCLK sit on different contacts. Which footprint to use depends on the debugger's connector — see the cable list.
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 · JTAG · UART · ST-LINK (STDC14) · Other assignments