CCS Technical Documentation
System Module and User Interface
NSB-9
Issue 1 04/03
Nokia Corporation
Page 31
Flip position detection
Flip position detection is implemented with HALL sensor switch (TLE4917) and magnet.
HALL switchs is located in engine top side, and magnet is inside the flip mechanics. HALL
switch output is connected to UEM KEYB1 AD input. Trigger level is 2.27V(min),
2.5V(typ), 2.69V(max) with 15...40mV hysteresis. HALL switch senses the possible pres-
ence of a magnet located inside the flip. Sensing is done by polling, the device wakes up
every 140ms and stays awake about 50us. When the flip is closed the output sensor is
floating , and an external 100k pull-up resistor is sets the line to 2.78V. Opening the flip
will move the magnet away from the sensing distance, and sensor output is driven down.
IR Module
The IR interface, when using 1.8V transceiver, is designed into the UPP. The IR link sup-
ports speeds from 9600 bit/s to 1.152 MBit/s up to distance of 80cm (2 feet 7 inches).
Transmission over the IR if half-duplex.
IR transceiver can be set into shut-down mode by setting SD pin to logic ’1’ for low cur-
rent consumption. Shut-down mode is used all the time when IR transceiver is not in
use.
SIM Interface
UEM contains the SIM interface logic level shifting. SIM interface can be programmed to
support 3V and 1.8V SIMs. SIM supply voltage is selected by a register in the UEM. It is
only allowed to change the SIM supply voltage when the SIM IF is powered down.
The SIM power up/down sequence is generated in the UEM. This means that the UEM
generates the RST signal to the SIM. Also the SIMCardDet signal is connected to UEM.
The card detection is taken from the BSI signal, which detects the removal of the battery.
The monitoring of the BSI signal is done by a comparator inside UEM. The SIM interface
is powered up when the SIMCardDet signal indicates ”card in”. This signal is derived from
the BSI signal.
Table 23: SIMCARDet Detection
The whole 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).
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.
Parameter
Variable
Min
Typ
Max
Unit
SIMCARDet, BSI comparator
Threshold
Vkey
1.94
2.1
2.26
V
SIMCardDet, BSI comparator
Hysteresis (1)
Vsimhyst
50
75
100
mV