Pcm Interface - Quectel M35 User Manual

Differential
AOUT2
Output
Single-ended
3.9.

PCM Interface

Pulse-code modulation (PCM) is a converter that changes the consecutive analog audio signal to discrete
digital signal. The whole procedure of Pulse-code modulation contains sampling, quantizing and
encoding.
M35 supports PCM interface. It is used for digital audio transmission between the module and the device.
This interface is composed of PCM_CLK, PCM_SYNC, PCM_IN and PCM_OUT signal lines.
The module disables PCM interface by default. AT command ―AT+QPCMON‖ is used to configure PCM
interface.
Table 13: Pin Definition of PCM Interface
Pin NO. Pin Name
12 PCM_SYNC
26 PCM_CLK
41 PCM_OUT
42 PCM_IN
NOTE
1)
When using the PCM interface, STATUS pin can be used as PCM_SYNC pin, RI pin can be used as
PCM_CLK pin.
M35_User_Manual
Ref level
Load resistance
Reference level
Load resistance
Reference level
Description
PCM frame synchronization output
PCM clock output
PCM data output
PCM data input
Confidential / Released
0
8
0
8
0
GSM/GPRS Module Series
M35 User Manual
4.8 Vpp
Load Resistance
2×VBAT Vpp
Load Resistance
VBAT Vpp
1)
Alternate Function
STATUS
RI
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