LTE Standard Module Series
EC25 Mini PCIe Hardware Design
EC25_Mini_PCIe_Hardware_Design 31 / 79
PCM_CLK
PCM_SYNC
PCM_DOUT
MSB
LSB
PCM_DIN
125us
MSB
1
2
32
31
LSB
Figure 9: Timing in Auxiliary Mode
Clock and mode can be configured by AT command, and the default configuration is master mode using
short frame synchronization format with 2048kHz PCM_CLK and 8kHz PCM_SYNC. In addition, EC25
Mini PCIe’s firmware has integrated the configuration on some PCM codec’s application with I2C interface.
Please refer to
document [2]
for details about
AT+QDAI
command.
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
Digital audio (PCM) function is only supported on
Telematics
version.
NOTE