Pcm And I2C Interfaces - Quectel EG25-G Hardware Design

Table 9: Pin Definition of Main UART Interface
Pin Name
UART_RX
UART_TX
UART_CTS
UART_RTS
The signal level of main UART interface is 3.3 V. When connecting to the peripheral MCU/RAM,
customers need to pay attention to the signal direction. The reference circuit is as follows:
MCU/ARM
TXD
RXD
GND
Voltage level: 3.3 V

NOTE
AT+IPR can be used to set the baud rate of the main UART, and AT+IFC can be used to set the hardware
flow control (hardware flow control is disabled by default). Please refer to document [2] for details.

3.7. PCM and I2C Interfaces

EG25-G Mini PCIe provides one Pulse Code Modulation (PCM) digital interface and one I2C interface.
The following table shows the pin definition of PCM and I2C interfaces that can be applied in audio codec
design.
EG25-G_Mini_PCIe_Hardware_Design
Pin No. I/O
11 DI
13 DO
23 DI
25 DO
RTS
CTS
Figure 7: Reference Circuit of Power Supply
LTE Standard Module Series
EG25-G Mini PCIe Hardware Design
Power Domain Description
3.3 V UART receive data
3.3 V UART transmit data
3.3 V UART clear to send
3.3 V UART request to send
UART_TXD
UART_RXD
UART_RTS
UART_CTS
GND
Voltage level: 3.3 V
Module
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