NL865B1 HW Design Guide
1VV0301450 Rev. 1
Page
41
of
72
2017-11-20
5.5.1.2.
MODEM SERIAL PORT 2
The secondary serial port on the NL865B1 is a CMOS1.8V with only TX signal which is
used for logging.
The signals of the NL865B1 serial port are:
PAD
Signal
I/O
Function
Type
NOTE
45
TX_AUX
O
Auxiliary UART (TX Data
to DTE)
CMOS
1.8V
Main Debug & logging
port
NOTE:
In order to avoid a back powering effect it is recommended to avoid
having any HIGH logic level signal applied to the digital pins of the
NL865B1 when the module is not supplied or during a
powerup/reboot transition.
Using bidirectional level translators which do not support High Z
mode during power off is not recommended.
