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8.1
Initialization
Immediately following power-on, the contents of all internal
registers and of the RAM are undefined. A RES pulse
must be applied. Attention should be paid to the
possibility that thedevice may be damaged if not properly
reset.
8.9
Set VOP value
The operation voltage VLCD can be set by software.
The values are dependent on the liquid crystal selected.
VLCD= a + (VOP6to VOP0) × b [V]. In the PCD8544,
a = 3.06 and b = 0.06 giving a program range of
3.00 to 10.68 at room temperature.
Note that the charge pump is turned off if VOP6to VOP0 is
set to zero.
For Mux 1 : 48, the optimum operation voltage of the liquid
can be calculated as:
(2)
where Vth is the threshold voltage of the liquid crystal
material used.
Caution, as VOP increases with lower temperatures,
care must be taken not to set a VOP that will exceed the
maximum of 8.5 V when operating at ?25 °C