GSM/GPRS Module Series
M85 Hardware Design
M85_Hardware_Design Confidential / Released 20 / 88
ringtone output.
Network Status Indicator
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
NETLIGHT
4
O
Network status
indication
VOHmin=
0.85×VDD_EXT
VOLmax=
0.15×VDD_EXT
If unused, keep
this pin open.
UART Port
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
DTR
47
I
Data terminal ready
VILmin=0V
VILmax=
0.25×VDD_EXT
VIHmin=
0.75×VDD_EXT
VIHmax=
0.2
VOHmin=
0.85×VDD_EXT
VOLmax=
0.15×VDD_EXT
If only use TXD,
RXD and GND to
communicate,
recommended
connecting RTS
to GND via 0R
resistor and
keeping other
pins open.
RXD
50
I
Receive data
TXD
49
O
Transmit data
RTS
51
I
Request to send
CTS
48
O
Clear to send
RI
46
O
Ring indication
DCD
45
O
Data carrier detection
Debug Port
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
DBG_TXD
42
O
Transmit data
Same as above
If unused, keep
these pins open.
DBG_RXD
43
I
Receive data
Auxiliary Port
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
TXD_AUX
40
O
Transmit data
Same as above
If unused, keep
these pins open.
RXD_AUX
41
I
Receive data
SIM Interface
PIN NAME
PIN NO.
I/O
DESCRIPTION
DC
CHARACTERISTICS
COMMENT
