GSM/GPRS Module Series
M85 Hardware Design
M85_Hardware_Design Confidential / Released 58 / 88
PCM_CLK
PCM_SYNC
PCM_OUT
PCM_IN
12 11 10
9
8
7
6
5
4
3
2
1
0
12 11 10
9
8
7
6
5
4
3
2
1
0
MSB
MSB
Zero padding
Zero padding
Figure 39: Short Synchronization & Zero Padding Diagram
3.11.3. Reference Design
M85 can only work as a master, providing synchronization and clock source. The reference design is
shown as below.
PCM_SYNC
PCM_CLK
PCM_OUT
PCM_IN
PCM_SYNC
PCM_CLK
PCM_IN
PCM_OUT
Module
(Master)
Peripheral
(Slave)
Figure 40: Reference Design for PCM
3.11.4. AT Command
There are two AT commands about the configuration of PCM are listed as below.
AT+QPCMON
can configure operating mode of PCM.
AT+QPCMON= mode,Sync_Type,Sync_Length,SignExtension,MSBFirst
.