# Using Nucleo STLink to Flash Off-board Chips

### Standard Board Interface

| Pin | Signal (DUT's side) | Color                                     |
| --- | ------------------- | ----------------------------------------- |
| 1   | GND                 | <mark style="color:orange;">Brown</mark>  |
| 2   | 3V3                 | <mark style="color:red;">Red</mark>       |
| 3   | SWCLK               | <mark style="color:orange;">Orange</mark> |
| 4   | SWDIO               | <mark style="color:yellow;">Yellow</mark> |
| 5   | RX (STLINK -> DUT)  | <mark style="color:blue;">Blue</mark>     |
| 6   | TX (DUT -> STLINK)  | <mark style="color:green;">Green</mark>   |

### Nucleo Pinout

<figure><img src="https://1287130752-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FvVJ0h2a4qMIhB1I8GdV8%2Fuploads%2Fgit-blob-e5342a51bfaff3d6e4e7ba71716f8d7816dd4b39%2Fimage.png?alt=media" alt=""><figcaption></figcaption></figure>

### Example Connection

<figure><img src="https://1287130752-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FvVJ0h2a4qMIhB1I8GdV8%2Fuploads%2Fgit-blob-9c3c44dc764693cb90049bbd67e25010d2ea2335%2Fimage.png?alt=media" alt=""><figcaption></figcaption></figure>