Nokia 6220 Service Manual

CCS Technical Documentation

System Module and User Interface

                                 

Company confidential 

RH-20

Issue 1  10/2003

  Nokia Corporation.

Page 31

The SIM interface is powered up when the SIMCardDet signal indicates "card in". This 
signal is derived from the BSI signal. 

The entire SIM interface locates in two chips: UPP and UEM. 

The SIM interface in the UEM contains power up/down, port gating, card detect, data 
receiving, ATR-counter, registers and level shifting buffers logic. The SIM interface is the 
electrical interface between the Subscriber Identity Module Card (SIM Card) and mobile 
phone (via UEM device). 

The data communication between the card and the phone is asynchronous half duplex. 
The clock supplied to the card is in GSM system 1.083 MHz or 3.25 MHz. 

ACI is a point-to-point, bi-directional serial bus. ACI has two main features: 

1)The inser-

tion and removal detection of an accessory device 

2) acting as a data bus, intended 

mainly for control purposes. A third function provided by ACI is to identify and authenti-
cate the specific accessory which is connected to the System interface. 

SIMCARDet, BSI comparator Threshold

Vkey

1.94

2.1

2.26

V

SIMCARDet, BSI comparator Hysteresis (1)

Vsimhyst

50

75

100

mV

C5 C6 C7 

C1  C2  C3 

SIMRst 

From 
Battery

 

 

 

C8 

C4 

SIMRst