Uart Interface - Quectel EG915U-EU Manual

The following figure shows a reference design of PCM interface with external codec IC.
External 26MHz Crystal
PCM_SYNC
PCM_DOUT
Module
Figure 22: Reference Circuit of PCM Application with Audio Codec

4.6. UART Interface

The module provides 3 UART interfaces and the following shows their features:
⚫
The main UART interface supports 4800 bps, 9600 bps, 19200 bps, 38400 bps, 57600 bps, 115200
bps, 230400 bps, 460800 bps and 921600 bps baud rates, and the default is 115200 bps. This
interface is used for data transmission and AT command communication.
⚫
The debug UART interface supports 921600 bps baud rate. It is used for the output of partial logs.
⚫
Auxiliary UART.
The following tables show the pin definition of main UART interface.
Pin definition of the UART interface is here as follows:
Table 16: Pin Definition of UART Interface
Pin Name
MAIN_CTS
MAIN_RTS
MAIN_RXD
EG915U-EU_Hardware_Design
0R
PCM_CLK
PCM_DIN
I2C_SCL
I2C_SDA
1.8 V
Pin No. I/O
36 DO
37 DI
34 DI
MICBIAS
MCLK
INP
BCLK
INN
LRCK
DAC
ADC
LOUTP
SCL
SDA
LOUTN
Codec
Description
Main UART clear to send
Main UART request to send
Main UART receive
LTE Standard Module Series
Comment
1.8 V power domain
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