UM11158 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2022. All rights reserved.
User manual Rev. 1.6 — 17 March 2022  10 of 24
 
NXP Semiconductors
UM11158
LPCXpresso55S69/55S28 Development Boards
• MCUXpresso IDE version 11.1.1 or later 
• SEGGER J-Link drivers version 6.72 or later. When using J-Link probes with 
non-SEGGER IDEs care should be taken to ensure the IDE being used is referencing 
the correct version of the driver. 
3.2  Starting a debug session using the on-board (Link2) Debug Probe
By default, the Board is configured to use the on-board Debug Probe (Link2) to debug the 
on-board target (LPC55Sxx), using the CMSIS-DAP debug protocol pre-programmed into 
the Link2 Flash memory. The MCUXpresso IDE or other development tools that support 
the CMSIS-DAP protocol can be used in the default configuration. Check with your 
toolchain vendor for availability of specific device support packs for the LPC55Sxx series 
devices. 
Note that when using the MCUXpresso IDE, the on-board Link2 can also be booted in 
DFU mode by installing a jumper on J4; if this is done then the IDE will download 
CMSIS-DAP to the probe as needed. Using DFU boot mode will ensure that the most 
up-to-date / compatible firmware image is used with the MCUXpresso IDE. 
NOTE: if the Debug Probe is set up to boot in DFU mode, the USB bridge functions 
(virtual COM port) and Debug Probe features will not be available if the board is not first 
initialized by the MCUXpresso IDE. 
3.2.1 Installation steps for use with MCUXpresso IDE
Download and install the MCUXpresso IDE.
Configure and download an SDK package (with the MCUXpresso IDE tool chain option 
selected) from the MCUXpresso SDK Builder utility (http://mcuxpresso.nxp.com).
Recommended: Install J4 to force the Link2 Debug Probe to boot in DFU mode (see notes 
above).
Ensure jumper -- is fitted in position -- (local target powered), and -- is not installed (target 
SWD enabled). These are the default positions set during board manufacture.
Connect the board to the USB port of your host computer, connecting a micro USB cable 
to connector P6. The board will boot and run the pre-installed demo.
Allow about 10 seconds for the LPCXpresso55S69/S28 Board to enumerate for the first 
time; the device will appear as "LPC Device". 
If the first attempt to debug a project fails in the IDE, cancel the debug session and 
repower the board. On some machines the drivers take longer to enumerate for the first 
time, so these steps should correct this issue. 
The board is now ready to be used with the MCUXpresso SDK examples for the 
LPCXpresso55S69/55S28. 
When the board is used for the first time, it is recommended to force the LPC55Sxx target 
into a known state by performing an ISP boot before attempting to run your first example 
code. This can be achieved by pressing and holding down the ISP button while pressing 
and releasing the reset button or installing the LPC55Sxx ISP jumper.