UM11158
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User manual
Rev. 1.6 — 17 March 2022
13 of 24
NXP Semiconductors
UM11158
LPCXpresso55S69/55S28 Development Boards
4.1 Link2 boot LED
LED DS2 is the Link2 MCU BOOT0_LED indicator. This LED reflects the state of Link2
MCU pin P1_1. When the boot process fails, DS2 will toggle at a 1 Hz rate for 60
seconds. After 60 seconds, the Link2 MCU is reset.
4.2 Programming the Link2 firmware
As mentioned earlier in this section, it is not normally necessary to program the Link2
firmware. However, this can easily be accomplished using the supporting utility,
LPCScrypt.
To program the Link2 Flash the Link2 device (LPC432x) must be in DFU mode. If the
Link2 already has a valid image in the flash, it will need to be forced into DFU mode by
placing a jumper shunt on J4 (DFU), and power cycling (disconnecting then reconnecting
power via P6.) Link2 MCU programming is performed using the LPCScrypt utility (see
http://www.nxp.com/lpcscrypt). Instructions for using the tool are located at the same web
page
After installing LPCScrypt, use either the “Program LPC-Link2 with CMSIS-DAP” or
“Program LPC-Link2 with JLink” utilities provided in that installation to update the
firmware, following on-screen instructions.
4.3 VCOM port
The identifier of the VCOM port will vary between boards and hosts as each board will
enumerate with a unique identifier. On Windows, to determine the COM port, open the
Windows operating system Device Manager. This can be achieved by going to the
Windows operating system Start menu and typing “Device Manager” in the search bar. In
the device manager look under “Ports”; the LPC-LinkII UCom Port device and its name
should be visible. NOTE: this VCOM port will only appear if (a) the Debug Probe has been
programmed with the CMSIS-DAP firmware and the Debug Probe DFU link (J4) is
removed at power up, or (b) if the Debug Probe has been configured for DFU boot (J4
installed) at power up and MCUXpresso IDE has booted it (by starting a debug session.)
If the J-Link firmware image has been programmed into the Debug Probe and DFU boot
mode is not being used, then a VCOM device called Jlink CDC UART port will appear
instead of the LPC-LinkII UCom port.
Note that the VCOM port is not available when the Link2 Debug Probe is not powered.
4.4 Configuring the LPCXpresso55S69 to debug an off-board target
The LPCXpresso55S69 board’s Link2 Debug Probe may be used to debug an off-board
target MCU. The on-board Link2 Debug Probe is capable of debugging target MCU’s with
a VDDIO range of 1.6V to 3.6V. To keep the on-board target LPC55Sxx MCU from
interfering with the SWD interface, J5 must be fitted (note: the header for this jumper is not
installed during board production). The Link2 Debug Probe SWD should be connected by
a ribbon cable between the P1 connector to the off-board target MCU SWD interface.
Power the LPCXpresso55S69 board from the Link USB connector P6, and fit jumper J3
across pins 2 - 3 (External Target).
