User's Manual

LTE Module Series
EC25Hardware Design
EC25_Hardware_DesignConfidential / Released 43 / 90
3.11. UART Interfaces
The module provides two UART interfaces: the main UART interface and the debug UART interface. The
following shows their features.
 The main UART interface supports4800, 9600, 19200,38400,57600,115200,230400,460800,921600
and3000000bps baud rates, and the default is 115200bps. This interface is used for data
transmission and AT command communication.
 The debug UART interface supports 115200bps baud rate. It is used forLinux console and log output.
The following tables show the pin definition.
Table 11: Pin Definition of the Main UART Interface
Pin Name Pin No. I/O Description Comment
RI 62 DO Ring indicator 1.8V power domain
DCD 63 DO Data carrier detection 1.8V power domain
CTS 64 DO Clear to send 1.8V power domain
RTS 65 DI Request to send 1.8V power domain
DTR 66 DI Sleep mode control 1.8V power domain
TXD 67 DO Transmit data 1.8V power domain
RXD 68 DI Receive data 1.8V power domain
Table 12: Pin Definition of the Debug UART Interface
Pin Name Pin No. I/O Description Comment
DBG_TXD 12 DO Transmit data 1.8V power domain
DBG_RXD 11 DI Receive data 1.8V power domain
The logic levels are described in the following table.