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Copyright 2005© Siemens AG
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53
TD_Repair_L2.5_A70_A75_R1.0.pdf Release
1.0
7.8 Display Modules
The A70 display has a resolution of 101x64 pixels b/w. It contains a passive addressed F-
STN panel. The A75 display has a resolution of 101x80 pixels with a colour depth of 256 or
4096 colours. The colour depth is switch-selectable by software. It contains a passive
addressed STN panel where the colours are generated by colour filter (C-STN, Colour-Super
Twisted Nematic). Different sources are used for the displays. The modules use different
LCD-controllers. In order to guarantee a very efficient illumination the Amber LEDs are
mounted on a PCB on the module. In addition, all passive components necessary to drive an
LCD are assembled on the module PCB. Further, the hardware coding is also implemented
on the module PCB. Thus, the only interconnections to the Siemens PCB are the data lines
and the power supply lines of the controller and the amber LEDs. The interface is realised by
a spring connector with 10 interconnections, which is assembled on the Siemens PCB.
Pin Name
Remarks
1 LCD_CS
Chip
select
2 LCD_RESET
Reset
3 LCD_RS
Register
select
4 LCD_CLK Clock
5 LCD_DAT Data
line
6
2.9V
Power supply display controller
7 GND
GND
8
LCD_LED2_A Power supply display led 2
9
LIGHT_K
Switched GND for display led 1 and led 2
10
LCD_LED1_A Power supply display led 1
Required voltage for the display illumination is
LCD_LED1_A
and
LCD_LED2_A
.