Product Info

LTE Standard Module Series
EG95 Series Hardware Design
EG95_Series_Hardware_Design
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3.12.
PCM and I2C Interfaces
EG95 provides one Pulse Code Modulation (PCM) digital interface for audio design, which supports the
following modes and one I2C interface:
Primary mode (short frame synchronization, works as both master and 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
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 also 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 256 kHz, 512 kHz, 1024 kHz or 2048 kHz PCM_CLK and an 8 kHz, 50% duty cycle PCM_SYNC.
EG95 supports 16-bit linear data format. The following figures show the primary modes timing relationship
with 8 kHz PCM_SYNC and 2048 kHz PCM_CLK, as well as the auxiliary modes timing relationship with
8 kHz PCM_SYNC and 256 kHz PCM_CLK.
125 μs
PCM_CLK
1 2
PCM_SYNC
255 256
MSB
LSB
MSB
PCM_DOUT
MSB LSB
MSB
PCM_DIN
Figure 22: Primary Mode Timing