Product Info

LTE Standard Module Series
EC25 Mini PCIe Hardware Design
EC25_Mini_PCIe_Hardware_Design 32 / 80
⚫ Primary mode (short frame synchronization, works as either master or slave)
⚫ Auxiliary mode (long frame synchronization, works as master only)
⚫
The digital audio (PCM) function is only supported on Telematics version.
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 7: 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.
NOTE