11
Pin Name
Pin
I/O
Description
Notes
RXD1
36
I
COM1 Receive
Data
COM1 input, leave unconnected
if not used
TXD2
37
O
COM2
Transmit Data
COM2 output, leave
unconnected if not used
RXD2
38
I
COM2 Receive
Data
COM2 input, leave unconnected
if not used
TXD3
39
O
COM3
Transmit Data
COM3 output, leave
unconnected if not used
RXD3
40
I
COM3 Receive
Data
COM3 input, leave unconnected
if no use
System
FRESET_N
22
I
Hardware
Reset (low
effective)
Restore factory settings by
lowering FRESET_N for no less
than 5 seconds
PPS
44
O
PPS signal
PPS
EVENT
45
I
EVENT signal
Event
3.4
PCB Packaging
Figure 3-3 UM4B0 recommended PCB Packaging (unit: mil, in brackets: mm)
