User Manual

PCI Express MiniCard Hardware Integration Guide
34 Proprietary and confidential 213XXXX
XIM Interface
The EM is designed to support one SIM (Subscriber Identity Module) or RUIM
(Removable User Identity Module). SIM is a smart card developed for GSM
networks while RUIM is for CDMA cellular systems. Each provides personal
user information that allows a mobile to attach to the wireless network. The XIM
feature provides the user with handset independence.
There are four required and one optional signals in the XIM interface. These are
defined in Table 5 with an example circuit (EM3420) shown in Figure 10.
Some EM models contain the voltage regulator for the XIM interface, while
others provide an enable signal. See the EM Reference Guide for your EM
model for details.
Table 5: XIM pins
Pin name RUIM pin
number
Function
XIM_VCC 1 XIM VCC
/XIM_RESET 2 Active low XIM reset
XIM_CLK 3 Serial clock for XIM data.
XIM_DATA 4 Bi-directional XIM data line