
GSM/GPRS Module
M85 Hardware Design
M85_Hardware_Design Confidential / Released 21 / 92
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
Dual-SIM interface
PIN NAME
PIN
NO.
I/O DESCRIPTION
DC
CHARACTERISTICS
COMMENT
SIM1_VDD
56
O
Power supply for SIM card
The voltage can be
selected by software
automatically. Either
1.8V or 3V.
All signals of SIM
interface should be
protected against
ESD with a TVS
diode array.
Maximum trace
length is 200mm
from the module
pad to SIM card
holder.
SIM2_VDD
71
SIM1_CLK
55
O
SIM clock
3V
:
VOLmax=0.4
VOHmin=
0.9×SIM_VDD
1.8V:
VOLmax=
0.12×SIM_VDD
VOHmin=
0.9×SIM_VDD
SIM2_CLK
72
SIM1_
DATA
54
I/O
SIM data
3V
:
VOLmax=0.4
VOHmin=
SIM_VDD-0.4
1.8V:
VOLmax=
0.15×SIM_VDD
VOHmin=
SIM2_
DATA
73
Quectel
Confidential