Quectel EC20 User Manual

LTE Module Series
EC20 Mini PCIe Hardware Design
EC20_Mini_PCIe_Hardware_Design Confidential / Released 22 / 36
3.7. PCM and I2C Interface
The following table shows the pin definition of PCM interface that can be applied in audio codec design.
Table 9: PCM and I2C Pin Definition
EC20 Mini PCIe provides one PCM digital interface, which supports 8-bit A-law and μ-law, 16-bit linear
data formats and the following modes:
 Primary mode (short sync, works as either master or slave)
 Auxiliary mode (long sync, 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, PCM_CLK supports 128kHz,
256kHz, 512kHz, 1024kHz, 2048kHz and 4096kHz. The following figure shows timing relationship in
primary mode with 8kHz PCM_SYNC and 2048kHz PCM_CLK.
Pin No.
Pin Name
I/O
Power Domain
Description
45
PCM_CLK
IO
1.8V
PCM clock signal
47
PCM_DOUT
DO
1.8V
PCM data output
49
PCM_DIN
DI
1.8V
PCM data input
51
PCM_SYNC
IO
1.8V
PCM frame sync
30
I2C_SCL
OD
1.8V
I2C serial clock, require external
pull-up to 1.8V
32
I2C_SDA
OD
1.8V
I2C serial data, require external
pull-up to 1.8V
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Quectel EC20 Specifications

General

Brand	Quectel
Model	EC20
Category	PCI Card
Language	English