User's Manual

M80 Hardware Design
M80_HD_V1.2 - 58 -
Table 16: Pin definition of the SIM interface
In Figure 33, the pin SIM_PRESENCE is used to detect whether the tray of the Molex SIM socket,
which is used for holding SIM card, is present in the card socket. When the tray is inserted in the
socket, SIM_PRESENCE is at low level. Regardless of whether the SIM card is in the tray or not,
the change of SIM_PRESENCE level from high to low level inspires the module to reinitialize
SIM card. In default configuration, SIM card detection function is disabled. Customer’s
application can use “AT+QSIMDET=1,0 ” to switch on and “AT+QSIMDET=0,0 ” to switch off
the SIM card detection function. For detail of this AT command, please refer to document [1].
When “AT+QSIMDET=1,0” is set and the tray with SIM card is removed from SIM socket, the
following URC will be presented.
+CPIN: NOT READY
When the tray with SIM card is inserted into SIM socket again and the module finishes
re-initialization SIM card, the following URC will be presented.
Call Ready
Module
SIM_VDD
SIM_RST
SIM_CLK
SIM_DATA
SIM_PRESENCE
22R
22R
22R
VCC
RST
CLK IO
VPP
GND
VDD_EXT
10K
100nF SIM_CARD
GND
GND
ESDA6V8V6
GNDPRESENCE
Figure 33: Reference circuit of the 8 pins SIM card
Name
Pin
Description
SIM1_VDD
56
Supply power for SIM Card. Automatic detection of
SIM card voltage. 3.0V±10% and 1.8V±10%.
Maximum supply current is around 10mA.
SIM1_DATA
54
SIM Card data I/O
SIM1_CLK
55
SIM Card clock
SIM1_RST
53
SIM Card reset
SIM_PRESENCE
57
SIM Card detect
SIM1_GND
52
SIM Card ground