Hardware layout and configuration UM1724
16/68 UM1724 Rev 14
6.1 Pre-cut PCB
The STM32 Nucleo board is divided into two parts: ST-LINK part and target STM32 part. 
The ST-LINK part of the PCB can be cut out to reduce the board size. In this case, the 
remaining target STM32 part can only be powered by VIN, E5V, and +3.3V on the ST 
morpho connector CN7, or VIN and +3.3V on ARDUINO
®
 connector CN6. It is still possible 
to use the ST-LINK part to program the main STM32 using wires between CN4 and SWD 
signals available on the ST morpho connector (SWCLK CN7 pin 15 and SWDIO CN7 pin 
13).
6.2 Embedded ST-LINK/V2-1
The ST-LINK/V2-1 programming and debugging tool is integrated into the STM32 Nucleo 
board.
The ST-LINK/V2-1 makes the STM32 Nucleo boards Mbed Enabled™.
The embedded ST-LINK/V2-1 supports only SWD for STM32 devices. For information about 
debugging and programming features, refer to the user manual ST-LINK/V2 in-circuit 
debugger/programmer for STM8 and STM32 (UM1075), which describes in details all the 
ST-LINK/V2 features.
The changes versus the ST-LINK/V2 version are listed below.
• New features supported on ST-LINK/V2-1:
– USB software re-enumeration
– Virtual COM port interface on USB
– Mass storage interface on USB
– USB power management request for more than 100 mA power on USB
• Features not supported on ST-LINK/V2-1:
–SWIM interface 
– Minimum supported application voltage limited to 3 V
• Known limitation:
– Activating the readout protection on ST-LINK/V2-1 target prevents the target 
application from running afterward. The target readout protection must be kept 
disabled on ST-LINK/V2-1 boards.
There are two different ways to use the embedded ST-LINK/V2-1 depending on the jumper 
states (see 
Table 4 and Figure 6):
• Program/debug the on-board STM32 (Section 6.2.2)
• Program/debug an MCU in an external application board using a cable connected to 
SWD connector CN4 (Section 6.2.4).
 
Table 4. Jumper states 
Jumper state  Description 
Both CN2 jumpers ON 
ST-LINK/V2-1 functions enabled for on-board programming 
(default) 
Both CN2 jumpers OFF 
ST-LINK/V2-1 functions enabled for external CN4 connector 
(SWD supported)