ARM JTAG programming and debugging interface which can also supply 5V power from USB and provide a standard RS232 serial interface.

See the Arduino due (clone pictured) for the command line operation.

 1 VREF      2 VREF
 3 TTRST_N   4 GND
 5 TTDI      6 GND
 7 TTMS      8 GND
 9 TTCK     10 GND
11 TRTCK    12 GND
13 TTDO     14 GND
15 TSRST_N  16 GND
17 NC       18 GND
19 5V       20 GND

Pin 19=5V if VREF=NC

DB9 plug

1 2 3 4 5
 6 7 8 9

1 DCD
2 RX
3 TX
4 DTR
5 GND
6 DSR
7 RTS
8 CTS
9 NC

Product page

User manual