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L830-EB-11 Hardware User Manual
Page 28 of 39
3.7.2 Body SAR
The L830 module supports Body SAR function by detecting the DPR pin. The voltage level of DPR is high
by default, and when the SAR sensor detects the closing human body, the DPR signal will be pulled down.
As the result, the module then lowers down its emission power to its default threshold value, thus
reducing the RF radiation on the human body. The threshold of emission power can be set by the AT
Commands. The definition of DPR signal as shown in the following table:
DPR signal
Function
High/Floating
The module keeps the default emission power
Low
Lower the maximum emission power to the threshold value of the module.
3.8 Digital Audio
The L830 module supports I2S digital audio interface and it supports the ordinary I2S mode and PCM
mode. The signal level of the I2S interface is 1.8V. Please refer to “FIBOCOM Digital Voice” description
for detailed application design. The definition of I2S signals is as follows:
Pin
Pin Name
I/O
Reset Value Pin Description
Type
20
I2S_CLK
O
PD
I2S clock
CMOS 1.8V
22
I2S_RX
I
PD
I2S serial data receive
CMOS 1.8V
24
I2S_TX
O
PD
I2S serial data transmit
CMOS 1.8V
26
I2S_WA
O
PD
I2S left and right channel clock (LRCK)
CMOS 1.8V
.
3.8.1 I2S Mode
The L830 module is connected to the Audio Codec via I2S interface, and the codec encodes the audio
data to implement the voice call function. For the scenario, the module works as the I2S master, and the
codec works as the I2S slave. I2S signal connection is shown in Figure 3-18:
Figure 3-18 I2S Signal Connection
