User Guide

PAMS
UIF Module DU8
NHB–3
Technical Documentation
Original 26/97
Page 5–11
For correct operation of the display, dc voltages between –VL1 and VL1 need
to be generated and fed back to the driver chip, at pins 4 to 8 inclusive (of X1).
The exact voltages depend on the relative values of the resistors R21, R37,
R38, R39, R40 and R33.
The display driver is connected to the radio module with a 4 bit data bus. Data
transfer is controlled with the following signals: R/W selects read or write opera-
tion (”0” = write, ”1” = read), Enable activates read/write operations and RS se-
lects the register (”0” : instruction register (writing) or busy flag (reading), ”1” :
data register).
SIM interface
The SIM interface is the electrical interface between the smart card used in the
GSM and PCN applications and the MCU via the ASIC. Four signals are used
between the SIM card and the ASIC: SIMDATA, SIMCLK, SIMRESET and
VSIM. Serial data is transferred between the card and the ASIC, the clock fre-
quency is 3.25 MHz. When there is no data transfer between the SIM card and
the HP the clock can be reduced to 1.625 MHz. Some cards allow to stop the
clock in that mode. The ASIC also generates the reset for the card and the sup-
ply voltage VSIM.
Power Distribution Diagram
Figure 3. Power Distribution
VBATT
VL1
VA1
GND
Call
LED
KEY/
LCD
Lights
VSIM
Buzzer
LCD
Keyboard
scan
Audio
SIM card
reader
AGND
Assembly
Construction
The assembly drawings show the physical positioning of all the components on
the flexis.