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NXP Semiconductors
UM11192
User Manual for LPCXpresso54S018M Development Board
UM11192
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2019. All rights reserved.
User manual
Rev. 1.0
— 13th February 2019
10 of 34
Circuit Ref
Description
Section
SW2, SW3,
SW4
ISP / User buttons
These switches can be used to force the LPC54S018J4M in to ISP boot
modes, as shown below. Note that ISP boot is also affected by OTP bit
settings, and behavior will also be modified based on port activity as the
boot ROM executes. Refer to the device User Manual for more
information. Signal is low when the button is pressed.
Mode / Boot source
ISP2
(P0-6)
ISP1
(P0-5)
ISP0
(P0-4)
Auto boot:
If OTP BOOT_SRC not set,
LPC54S018J4M will look for a valid
image in internal flash, then external
SPI flash, then external parallel flash.
High
High
High
USART/I2C/SPI boot
High
High
Low
SPI Boot:
Boot from SPI NOR flash connected to
Flexcomm 9. If no valid image is found,
ISP boot will commence. This board
does not have on-board SPI flash, but
the SPI port signals to support this are
available on connectors J9 and J13.
High
Low
High
Reserved
High
Low
Low
SPIFI boot:
Boot from internal flash memory. If no
valid image is found, ISP boot will
commence, depending on OTP bit
settings.
Low
High
High
USB0 (full speed) ISP DFU
Low
High
Low
USB1 (high speed) ISP DFU
Low
Low
High
The ISP pins are sampled by the LPC54S018J4M boot ROM code
immediately following reset, so to initiate an ISP boot press and hold the
required ISP buttons while pressing and releasing the reset button
(SW1.)
Following reset, these buttons may also be used by a user application.
Note: A board power cycle (holding down ISP required buttons while
power is applied) may be required to ensure correct driving of the ISP
pins when the EMC bus has been initialized, since these pins are shared
with the EMC D2-D3 pins, and the SDRAM chip select may float at reset.
SW5
User button
This button is connected to LPC54S018J4M port pin P1-1 and is
provided for user applications. Port P1-1 is pulled to ground when the
button is pressed.
J1
Ex5V power
Micro USB connection for power to the LPC54S018J4M target and
peripheral circuitry (excluding Link2 Debug Probe).