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UM11158
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© NXP B.V. 2019. All rights reserved.
User manual
Rev. 1.2 — 25 April 2019
17 of 24
NXP Semiconductors
UM11158
LPCXpresso55S69 Development Board
7.5.1 ISP (S1)
P0_5 is pulled up to VDD via a 2.2 kohm resistor; pressing this button will pull P0_5 low.
This port is read by the LPC55S69 boot code to determine if the MCU should enter In
System Programming (ISP) mode. The main purpose of this button is to force the
LPC55S69 into ISP mode at boot time; to do this hold down this button while pressing and
releasing the Reset button, or while connecting power to the board. While the main
purpose of ISP mode is to program the flash of the LPC55S69, forcing the MCU into this
mode places it into a known state in which development tools can gain debug control. If an
application in flash is crashing or disabling the SWD port unintentionally, then ISP mode
can be useful to recover control of the board. Refer to the LPC55S69 User Manual for
more information on ISP mode.
The ISP button can also be used in user application code. Care should be taken if P0_5 is
configured as an output driving high, since pressing this button will short it to ground.
Note that jumper J10 may also be used as a convenient way to always assert ISP when
the LPC55S69 is reset or powered up. This jumper is in parallel with S1.
7.5.2 User (S3) and Wake (S2) buttons
The User (S3) and Wake (S2) buttons are intended for user application use. These
buttons pull ports P1_9 (User) and P1_18 (Wake) low when the button is pressed.
100kohm resistors are used to pull these two ports to VDD then the buttons are not
pressed.
7.5.3 Reset
Pressing this button will assert reset to the LPC55S69 and to the Mikroe and Arduino
connector sites. Note that the Debug Probe (LPC4322) is not reset when this button is
pressed.
8. Expansion connectors
The LPCXpresso55S69 includes 3 expansion connector sets, incorporating support for
Arduino UNO R3, Mikroe Click and PMod standards. The Arduino UNO connector
footprint is surrounded by additional connectors that are compatible with other
LPCXpresso V3 boards. Pin out diagrams are provided below in
and
For further details, refer to the board schematics.
8.1 Mikroe Click Site
The connectors P23 and P24 provide a Mikroe Click module site for the wide range of
add-on modules available from MikroElektronika. Note that this site shares the same SPI,
I2C and UART connections as the Arduino/LPCXpresso V3 expansion connectors.
8.2 Host / PMod Connector
Connector P20 is a optional connector (not installed by default) which can provide
convenient access for a remote host to the SPI and I2C ports of the LPC55S69 that
support ISP mode. When setting up the Board to be used with a host, jumper P1 must be
installed to prevent conflict with the Link2 (which can also emulate an SPI or I2C host).
Jumper J4 can be used to force the LPC55S69 to boot in ISP mode, and connector P14