Sim Card Interface - LG -A120 Service Manual

3.7 SIM Card Interface

The MT6223 contains a dedicated smart card interface to allow the MCU access to the SIM card.
It can operate via 4terminals, using SIMVCC, SIMI/O, SIMRST, SIMCLK
The SIMVCC is used to control the external voltage supply to the SIM card. SIMRST is used as
the SIM card reset signal. SIMI/O and SIMCLK are used for data exchange purpose.
The SIM interface acts as a half duplex asynchronous communication port and its data format is
composed of ten consecutive bits: a start bit in state Low, eight information bits, and a tenth bit
used for parity checking.
Figure.3-7-1 SIM CARD Interface
34