Hardware Integration Guide
Rev 3 Sep.18
18
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4.5 I2S Interface (Digital Audio)
Note: Interface support is forthcoming.
The AirPrime BX310x provides a 4-wire I
2
S (digital audio) interface that can be used
to transfer serial digital audio to or from an external stereo DAC/ADC, and supports
the following features:
•
Modes—Master, Slave
•
Transmission format—Full duplex, Half duplex
•
Resolution (bits per frame)—8, 16, 32, 40, 48
•
Channels—Input, Output
•
Bit clock—10 kHz–40 MHz
•
Supported audio interfaces (forthcoming)—PDM (Pulse Density Modulation),
BT PCM (Pulse Code Modulation)
The interface uses the pins indicated in
4.6 General Purpose Input/Output (GPIO)
The AirPrime BX310x defines several GPIOs for customer use, as described in
and
.
Note: The pins carrying the ‘Alternate function’ GPIOs are multi-function. The alternate inter-
faces (SDIO or SPI) can be selected via an AT command.
Table 4-5: I2S Interface Pins
a
a. Leave open any pins that are not used.
Pin
Signal name
Direction
b
b. Signal direction with respect to the module.
Function
Voltage Level
16
I2S_MCLK
O
I2S MasterClock
VDD_PADS_BB
24
I2S_DO
O
I2S Data Out
25
I2S_DI
I
I2S Data In
26
I2S_LRCLK
I/O
I2S Left-Right Clock (Word Select)
27
I2S_BCLK
I/O
I2S Bit Clock
Table 4-6: GPIO Pins (Dedicated)
a
a. Leave open any pins that are not used.
Pin
Signal Name
Direction
Default State
Function
Voltage Level
14
GPIO(5)
I/O
Pull high
b
b. Pulled high internally
General purpose I/O VDD_PADS_BB
35
GPIO(27)
I/O
No pull
c
c. Internal configuration—no internal pull-ups
