Cavli Wireless C100QM/C10QM Hardware Manual
46
recognize or drop the card. Therefore, the card slot should be placed as far as possible
from the RF radiation of the antenna. The card trace should be as far away as possible
from the RF, power supply and high-speed signal lines.
✧
The UIM_DATA has been internally pulled up to VDD_EXT through a 47K resistor,
and no external pull-up is required.
✧
UIM_DET is the USIM card insertion or non-insertion detection pin. It is high by
default. The SIM card status can be detected by this PIN during hot plug application.
✧
To avoid transient voltage overload, the USIM interface requires a 22R resistor in
series with each other on the signal line path.
✧
The ground of the USIM deck and the ground of the module should maintain good
connectivity.
3.7.2 UIM_DET Hot Swap Reference Design
The C100QM/C10QM module supports the USIM card hot plug function.
The UIM_DET pin acts as an input detection pin to determine whether the USIM card is
inserted or not. The UIM_DET pin defaults to a pull-up high. The hot-swap function can
be turned on or off with AT+HOSCFG, which is turned off by default (see the
C100QM/C10QM AT command set for details).
Table 3-12 SIM card hot swap detection pin definition
NO.
AT command
UIM_DET
status
Functional description
1
AT+HOSCFG=1,1
high
SIM card insertion, UIM_DET is high
2
AT+HOSCFG=1,0
low
SIM card insertion, UIM_DET is low