LTE Standard Module Series
EC21 Mini PCIe Hardware Design
EC21_Mini_PCIe_Hardware_Design 31 / 67
The following figure shows a reference design of PCM interface with an external codec IC.
PCM_DIN
PCM_DOUT
PCM_SYNC
PCM_CLK
I2C_SCL
I2C_SDA
Codec
Module
1.8V
2.
2K
2.
2K
BCLK
FS
DACIN
ADCOUT
SCLK
SDIN
B
IA
S
MIC_BIAS
MIC+
MIC-
SPKOUT-
Figure 10: Reference Circuit of PCM Application with Audio Codec
1)
The digital audio (PCM) function is only supported on
Telematics
version.
3.8. Control and Indication Signals
The following table shows the pin definition of control and indication signals.
Table 11: Pin Definition of Control and Indication Signals
Pin Name
Pin No.
I/O
Power Domain
Description
RI
17
DO
3.3V
Output signal used to wake up the host
DTR
31
DI
3.3V
Sleep mode control
W_DISABLE#
20
DI
3.3V
Airplane mode control;
Pulled up by default;
Active low.
PERST#
22
DI
3.3V
Fundamental reset signal;
Active low.
LED_WWAN#
42
OC
LED signal for indicating the network status
of the module;
Active low.
NOTE
