Pcm Interface - Quectel RM500Q-AE Manual

reserved on bottom side) must be used for the firmware upgrade. Also, the firmware can be upgraded by
the PCIe Card EVB, which could be inserted into a PC. For more details, see document [1].
3.8.3.10.

PCM Interface*

RM500Q-AE&RM502Q-AE module supports audio communication via Pulse Code Modulation (PCM)
digital interface. The PCM interface supports the following modes:
⚫
Primary mode (short frame synchronization): the module works as both master and slave
⚫
Auxiliary mode (long frame synchronization): the module works as master only
In primary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising
edge. The PCM_SYNC falling edge represents the MSB. In this mode, the PCM interface supports 256
kHz, 512 kHz, 1024 kHz or 2048 kHz PCM_CLK at 8 kHz PCM_SYNC, and also supports 4096 kHz
PCM_CLK at 16 kHz PCM_SYNC.
In auxiliary mode, the data is sampled on the falling edge of the PCM_CLK and transmitted on the rising
edge. The PCM_SYNC rising edge represents the MSB. In this mode, PCM interface operates with a 256
kHz PCM_CLK and an 8 kHz, 50 % duty cycle PCM_SYNC only.
The module supports 16-bit linear data format. The following figures show the primary mode's timing
relationship with 8 kHz PCM_SYNC and 2048 kHz PCM_CLK, as well as the auxiliary mode's timing
relationship with 8 kHz PCM_SYNC and 256 kHz PCM_CLK.
PCM_CLK
PCM_SYNC
PCM_DOUT
PCM_DIN
RM500Q-AE&RM502Q-AE_Hardware_Design
125 μs
1 2
MSB
MSB
Figure 2021: Primary Mode Timing
RM500Q-AE&RM502Q-AE Hardware Design
255 256
MSB
LSB
MSB
LSB
5G Module Series
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