Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 44 of 92 21.12.2001
3.7 SIM interface
The baseband processor has an integrated SIM interface compatible with the ISO 7816-3 IC
Card standard. This is wired to the host interface (ZIF connector) in order to be adapted to
an external SIM card holder.
Six pins on the ZIF connector are reserved for the SIM interface. Further to the five wire SIM
interface according to GSM 11.11, the CCIN pin has been added. The CCIN pin serves to
detect mechanically whether or not a card is inserted into the card holder. The default level
of CCIN is low (internal pull down resistor, no card inserted). It must go high when the card is
inserted.
To take advantage of this feature, an appropriate contact is required on the card holder. For
example, this is true for the model supplied by Molex Deutschland GmbH, which has been
tested to operate with TC35/TC37 and is part of the Siemens reference setup for type
approval (Molex ordering number 91228-0001). When designing the host application, ensure
that the card holder on the host application provides a high signal when the SIM card is
present.
It is recommended that the total cable length between the ZIF connector pins on TC35/TC37
and the pins of the card holder does not exceed 200 mm in order to meet the specifications
of GSM Recommendations 11.10 and to satisfy the requirements of EMC compliance.
Note: Before removing the SIM card or inserting a new one be sure that the GSM engine
has been powered down as described in Chapter 3.3.
Table 12: Signal of the SIM interface (ZIF connector)
Signal Description
CCRST Chipcard reset, provided by baseband processor
CCCLK Chipcard clock, various clock rates can be set in the baseband processor
CCIO Serial data line, input and output.
CCIN Input on the baseband processor for detecting the SIM in the holder; if the SIM is removed
during operation the interface is shut down immediately to prevent destruction of the SIM.
CCVCC SIM supply voltage.
CCGND Separate ground connection for SIM card to improve EMC
3.7.1 Approval considerations
European countries: For Europe (R&TTE) it is not mandatory to provide an extra approval
for the SIM card holder used in an TC35/TC37 application. However,
should your application be enhanced beyond the certified Siemens
reference setup, it is recommended that you apply for an additional
approval.
Other countries: You may be required to obtain an extra approval when your SIM card
holder differs from the SIM interface schematics detailed in this
chapter.