Naviscroll - Nokia RM-333 Service Manual

RM-333; RM-334; RM-335
System Module and User Interface
Figure 76 Light segments

Naviscroll

HW53 uses Quantum QT12C15 as Naviscroll Driver. As shown in Figure 1, it is interfaced to RAPIDO via SPP I2C
bus for control and data, two change lines TouchPadInt and KeyInt used by Naviscroll Driver to report to
RAPIDO any changes in the touchpad state or changes in the S60 key states, Rst is used as a reset signal from
RAPIDO to Naviscroll Driver.
On the other side, Naviscroll Driver interfaces Naviscroll touchpad and S60 keys as 3x4 matrix. When there is
a change in the touchpad state i.e. when the finger is scrolled over the naviscroll touchpad the Naviscroll
Driver gives an interrupt to RAPIDO via TouchPadInt line by pulling it low. Similarly when any of the S60 keys
is pressed the Naviscroll Driver gives an interrupt to RAPIDO via KeyInt line by pulling it low. When receiving
either of the Interrupts, RAPIDO performs an I2C data read from Naviscroll Driver internal registers to
determine Naviscroll touchpad XY position change if TouchPadInt was detected and to determine which S60
keys were pressed if KeyInt was detected. After that, the interrupt lines change state from low to high. 2V8
voltage regulator located on the UI flex supplies power for the Naviscroll driver.
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