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UM11158
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© NXP B.V. 2019. All rights reserved.
User manual
Rev. 1.2 — 25 April 2019
15 of 24
NXP Semiconductors
UM11158
LPCXpresso55S69 Development Board
The Board can only be configured to support one of these ports as a host at a time (this is
a limitation of the board, not the LPC55S69). When either port is used as a host, power
must be supplied to the board via the +5V power only micro B USB port. Jumper J6 is
used to connect power from a load switch to the VBUS signal of the port selected; J6
should be placed in position 1-2 for USB1 or position 2-3 for USB0. If neither USB port is
being used as a USB host this jumper is not required.
6.2 USART header
Header P8 is provided as a convenient way to use an LPC55S69 USART with a serial to
USB cable. Flexcom 0 ports (P0_29 and P0_30) are used for this feature, since these
ports are assigned for USART ISP mode. Note that these ports are shared with the Link2
debug probe (LPC4322) and PMod connector; when using this header ensure that there
is no conflicting device connected to the PMod connector and that jumper P1 is installed
to disable the connection to the Link2. Always ensure the serial cable is only connected
when the board is powered to prevent the LPC55S69 being powered through this
TXD/RXD pins.
7. On-board peripherals
This section describes how the on-board peripheral devices of the Board are connected to
the LPC55S69 and relevant configuration options. For full details of these devices please
refer to the individual device datasheets. For circuit further details, refer to the board
schematics.
7.1 Audio Codec
The LPCXpresso55S69 board incorporates a Cirrus Logic (Wolfson) WM8904 audio
codec. This codec has both I2C (for control) and I2S (for data) interfaces.
The I2C interface of the codec is routed to Flexcomm 4 of the LPC55S69, the same
connection as used for the other I2C devices on the board; the Codec has an address of
0b0011010.
The Flexcomm 6 and Flexcomm 7 interfaces of the LPC55S69 are connected respectively
to the Codec for data sent to / receive from the Codec. The board design assumes pad
sharing between Flexcom 6 and Flexcom 7 for I2S connections.
I2S connections from the LPC55S69 are also connected to the Expansion connectors;
solder jumpers may be removed to disconnect the on-board codec if an external I2S
device is to be used instead.
Line input (J1) and line output (J2) 1/4” stereo jack sockets provide analog I/O
connections to the Codec. See schematic for further information.
Table 2.
Audio Codec port connections
Circuit reference
Port
Flexcoms
I2S SCK
P0_21
Flexcom 6 & 7, pad shared
I2S TX/RX Data
P0_20
Flexcom 6 & 7, pad shared
I2S WS
P0_19
Flexcom 6 & 7, pad shared
I2C SDA
P1_21
Flexcom 4
I2C SCL
P1_20
Flexcom 4