Uart Port Application - Fibocom NL668-LA Hardware User Manual

Pin Name I/O
RI O
DCD O
CTS O
RTS I
DTR I
TXD O
RXD I
Pin Name I/O
DBG_RXD I
DBG_TXD O

5.5.2 UART port application

The serial port level of NL668-LA series module is 1.8V, if the level of the client host system is 3.3V or
other, level translator needed between the module and the host. The reference design circuit of level
translator is shown as follows
The other level
translator
dotted line please refer to solid line part, but pay attention to signal connection direction.
Reproduction forbidden without Fibocom Wireless Inc. written authorization - All Rights Reserved.
FIBOCOM NL668-LA Series Hardware User Manual
Pin Num
62
63
64
65
66
67
68
Table 5- 10 Main Serial Port
Pin Num
11
12
Table 5- 11 Debug Serial Port
:
Figure 5- 12 UART Level Translate Reference 1
circuit is shown as Figure 5-13, The rest input and output circuit design of
Description
Ring indicator
Data carrier detection
Request to send
Clear to send
Data ready, sleep mode control
Module Transmit data
Module Receive data
Description
Module Receive data
Module Transmit data
Page 38 of 65