Sim Troubleshooting - Nokia RM-12 Troubleshooting Instructions

Nokia Customer Care

SIM troubleshooting

The whole SIM interface locates in two chips UPP8M and UEMKEdge. UEM contains the SIM
interface logic level shifting. UPP provides SIMClk through UEM to the SIM. SIM interface sup-
ports both 3 V and 1.8 V SIMs.
SIM
C5 C6 C7
C1 C2 C3
BSI line from battery
The SIM power up/down sequence is generated in the UEM. This means that the UEM gener-
ates 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. Monitoring of
the BSI signal is done by a comparator inside UEM. The threshold voltage is calculated from
the battery size specifications.
The SIM interface is powered up when the SIMCardDet signal indicates "card in". This signal
is derived from the BSI signal. SW tries first to power up the SIM with 1.8 V. If this does not
succeed power up is repeated with VSIM switched to 3 V.
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. The data baudrate is SIM
card clock frequency divided by 372 (by default), 64, 32 or 16.
Issue 1 11/2004
Figure 25: UPP & UEM SIM connections
GND
SIMDATA
SIMCLK
SIMRST
VSIM
UEM
SIMIF
register
BSI
Copyright©Nokia. All rights reserved
SIMIO
SIMIO
SIMClk
SIMClk
Data
Data
UIF Block
UEMInt
UEM
digital
CBusDa
logic
CBusEnX
CBusClk
RM-12
GND
UPP
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