NXP Semiconductors
LPCXpresso55S36UM
LPCXpresso55S36 Development Board User Manual
2.6 I2S interface
Inter-IC sound (I2S) is a three-wire serial bus with one data, one clock, and one word
select (frame trigger) signals. Each of the Flexcomm modules 0-5 of the target MCU
provides one channel pair of I2S. One of these modules can be set as I2S master and
others as I2S slaves. Each of the Flexcomm modules 6-7 of the target MCU provides four
channel pairs of I2S. These modules can only be set as I2S slaves.
In the LPCXpresso55S36 board, I2S connections are supported on Flexcomm modules
0, 2, 3, 4, and 6. The figure below shows the I2S diagram of the LPCXpresso55S36
board.
LPC5536
FC0
FC6
FC2
FC3
FC4
Audio codec
Audio jacks
I2S master
I2S slave
I2S master/slave
I2S slave
I2S slave
I2S slave
I2S master/slave
Audio
expansion
connector
Figure 8. I2S diagram
The table below shows the LPCXpresso55S36 I2S bus device map.
Device
I2S master
I2S slaves
Audio codec (U13)
FC0
FC3
Audio expansion connector (J44)
FC0/FC3
•
When FC0 is used as I2S master; FC2, FC3, FC4,
and FC6 are I2S slaves
•
When FC3 is used as I2S master; FC0, FC2, FC4,
and FC6 are I2S slaves
Table 14. I2S bus device map
2.6.1 Audio codec and audio expansion connector
The LPCXpresso55S36 board has an audio coder/decoder (codec) for encoding/
decoding audio data. The audio codec is connected to two audio jacks, one for receiving
input for audio codec and other for sending output from audio codec.
The board also provides an audio expansion connector, which can be used to connect an
external audio device. The routing of signals between the target MCU and audio codec
(or audio expansion connector) is controlled through various configuration resistors. The
configuration resistors of the audio codec are populated, allowing it to communicate to
the target MCU. The configuration resistors of the audio expansion connector are not
populated on the board.
LPCXpresso55S36UM
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User manual
Rev. 2 — 5 September 2022
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