Touchpad - Nokia RH-6 Series Baseband Description & Troubleshooting

RH-6
6 - BB Description & Troubleshooting
Reset timing
Reset timing characteristics are shown in the figure below.
Signal
RESX
Display power on/off sequence
Power on/off sequence if described in the figure below
VDDI
VDD
CSX
RESX

Touchpad

A 4-wire touchpad controller is the interface from UPP to the touchpad module. The
main function of this device is to convert the digital format control from engine to TP
controller. The control byte commands the controller to switch on/off the low on-
switches in ADC input to provide power/Gnd connection to touchpad plates. Then again
read the analog voltage data in AD input, convert it to digital signal and transmit to UPP
in serial mode. UPP cannot interface the controller directly with HW so the SPI
protocol interface is made with MCU SW.
The data is read from the touchpad plates using a Texas Instruments TSC2046 controller.
Page 26
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Figure 11: Reset timing
Table 13: Reset Timing
Symbol Parameter
tRW Reset pulse duration
tRT Reset cancel
t<1ms
t>100ns
Figure 12: Power on/off Sequence
© 2003 Nokia Corporation.
CCS Technical Documentation
Min Max Unit
200 ns
1500 ns
t<1ms
Issue 1 10/2003
tm
3-wire