Quectel LTE Standard Module Series - Page 26

LTE Standard Module Series
EG21-G Mini PCIe Hardware Design
EG21-G_Mini_PCIe_Hardware_Design 25 / 54
EG21-G Mini PCIe provides one PCM digital interface, which supports 16-bit linear data format and the
following modes:
 Primary mode (short frame synchronization, works as either master or slave)
 Auxiliary mode (long frame synchronization, 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
256kHz, 512kHz, 1024kHz or 2048kHz PCM_CLK at 8kHz PCM_SYNC, and also supports 4096kHz
PCM_CLK at 16kHz PCM_SYNC. The following figure shows the timing relationship in primary mode with
8kHz PCM_SYNC and 2048kHz PCM_CLK.
PCM_CLK
PCM_SYNC
PCM_DOUT
MSB
LSB
MSB
125us
1 2 256255
PCM_DIN
MSB
LSBMSB
Figure 8: Timing in Primary Mode
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, the PCM interface operates with a
256kHz, 512kHz, 1024kHz or 2048kHz PCM_CLK and an 8kHz, 50% duty cycle PCM_SYNC. The
following figure shows the timing relationship in auxiliary mode with 8kHz PCM_SYNC and 256kHz
PCM_CLK.
I2C_SDA
32
IO
1.8V
I2C serial data.
Require external pull-up to 1.8V.