User manual

LPC3250 Developer’s Kit v2 - User’s Guide
Page 40
Copyright 2013 © Embedded Artists AB
GPIO70
GPIO_00
GPIO42
GPO_14
4.25 SP15: I2S Audio Codec
The board contains an I2S audio codec based on UDA1380 from NXP. The codec is controlled via I2C
and audio data is transferred over the I2S bus.
The OEM Base Board supports different OEM Boards and the I2S signals can be located at two
different groups of signals from the OEM Board. Jumper JP22-JP27 selects which group of signals to
connect to the I2S interface of the UDA1380. For LPC3250 OEM Board, set all jumpers in lower
position (see picture below). Note that this is not the default setting of the jumpers when the
board is delivered.
The audio codec provides a mono microphone input, a stereo line input, a stereo line output and a
stereo headphone output. The board also has an on-board speaker. The right line output can be used
to drive the speaker. Signal GPIO40 (GPO_00 from the LPC3250) is also connected to the speaker via
JP29 (pos 1-2). By PWM-modulating this signal and audio signal can also be created.
See picture below for locating relevant components. The table below lists signal connections.
Figure 24 – I2S Audio Codec Interface
Signals
LPC3250
I2C-SDA
I2C1-SDA
I2C-SCL
I2C1-SCL
GPIO40
GPO_00
GPIO56
I2S1TX_CLK
GPIO57
I2S1TX_SDA
GPIO58
I2S1TX_WS
Speaker
SP1
Audio Connectors
Left-to-right:
J27, J28, J29, J30
Mic in, Line in, Line out, Headphone out
Audio Select
JP29
I2S Select
Left-to-right: JP22, JP23,
JP24, JP25, JP26, JP27, JP28