SARA-R4/N4 series - System Integration Manual
UBX-16029218 - R11
System description
Page 42 of 157
1.9.3
SPI interface
☞
The SPI interface is not supported by “00”, “01”, “02” and “52” product versions: the SPI interface pins
should not be driven by any external device.
SARA-R4/N4 series modules include a Serial Peripheral Interface for communication with compatible
external device.
The SPI interface can be made available as alternative function, in mutually exclusive way, over the digital
audio interface pins (
I2S_WA / SPI_MOSI
,
I2S_RXD / SPI_MISO
,
I2S_CLK / SPI_CLK
,
I2S_TXD / SPI_CS
).
1.9.4
SDIO interface
☞
The SDIO interface is not supported by “00”, “01”, “02” and “52” product versions: the SDIO interface
pins should not be driven by any external device.
SARA-R4/N4 series modules include a 4-bit Secure Digital Input Output interface (
SDIO_D0
,
SDIO_D1
,
SDIO_D2
,
SDIO_D3
,
SDIO_CLK
, and
SDIO_CMD
) designed to communicate with external compatible SDIO
devices.
1.9.5
DDC (I
2
C) interface
☞
The I
2
C interface is not supported by “00” and “01” product versions: the I
2
C interface pins should not
be driven by any external device.
SARA-R4/N4 series modules include an I
2
C-bus compatible DDC interface (
SDA
,
SCL
lines) available to
communicate with a u-blox GNSS receiver and with external I
2
C devices as an audio codec: the SARA-R4/N4
series module acts as an I
2
C master which can communicate with I
2
C slaves in accordance with the I
2
C bus
specifications
The
SDA
and
SCL
pins have internal pull-up to
V_INT
, so there is no need of additional pull-up resistors
on the external application board.
1.10
Audio
☞
Audio is not supported by “00”, “01”, “02” and “52” ” product versions: the I
2
S interface pins should not
be driven by any external device.
