Datasheet

Chapter 9 Liquid Crystal Display Driver (S08LCDV1)
MC9S08LC60 Series Data Sheet: Technical Data, Rev. 4
Freescale Semiconductor 127
9.2 External Signal Description
The LCD module has several external pins dedicated to power supply and also LCD frontplane/backplane
signaling. Table 9-3 itemizes all the LCD external pins. See the Pins and Connections chapter for
device-specific pin configurations.
9.2.1 BP[2:0]
This output signal vector represents the analog backplane waveforms of the LCD module. These signals
are connected to the back plane of the LCD panel.
9.2.2 FP[39:0]
This output signal vector represents the analog frontplane waveforms of the LCD module. These signals
are connected to the front plane of the LCD panel.
9.2.3 BP3/FP40
This signal vector represents either an analog frontplane or backplane waveform of the LCD module
depending on the configuration of the DUTY[1:0] bit field.
9.2.4 V
LCD
V
LCD
is the positive supply voltage for the LCD module waveform generation. V
LCD
can internally derive
from V
DD
or externally derive from voltage source range from 0.9 to 1.8 Volts. V
LCD
is connected to a
switch capacitor charge pump DC/DC converter (voltage doubler and voltage tripler) which is able to
generate double or triple V
LCD
in order to support either 3-V or 5-V LCD glass. V
LCD
is also connected
internally to an internal ADC channel in order to monitor the V
LCD
magnitude.
9.2.5 V
LL1
, V
LL2
, V
LL3
V
LL1
,V
LL2
, and V
LL3
are bias voltages for the LCD module driver waveforms. Internally generated using
the internal charge pump when it is enabled.
Table 9-3. Signal Properties
Name Port Function Reset State
3 backplanes BP[2:0], Backplane waveform signals that connect directly to the pads High impedance
40 frontplanes FP[39:0] Frontplane waveform signals that connect directly to the pads High impedance
Frontplane/backplane BP3/FP40 Switchable frontplane/backplane signal that connects directly
to the pads
High impedance
LCD voltage V
LCD
LCD supply voltage —
LCD bias voltages V
LL1
,
V
LL2
,
V
LL3
LCD bias voltages —
LCD charge pump capacitance V
cap1
,
V
cap2
Charge pump capacitor pins —