MC68HC908LJ12 Datasheet, PDF (320/413 Pages) Freescale Semiconductor, Inc – 8-bit microcontroller units

Liquid Crystal Display Driver (LCD)
When the LCD driver module is disabled (LCDE = 0), the LCD display
will be OFF, all backplane and frontplane drivers have the same
potential as V_DD. The resistor ladder is disconnected from V_DD to reduce
power consumption.
FP4
FP3
FP2
FP1
FP0/BP3
BP2
BP1
BP0
LCD FRONTPLANE DRIVER AND DATA LATCH
1/3
1/4
LCDE (LCDC)
STATE
CONTROL
1/1 1/3 1/4
PTC0/FP19
PTC1/FP20
PTC2/FP21
PTC3/FP22
PTC4/FP23
PTC5/FP24
PTC6/FP25
PTC7/FP26
Figure 16-2. LCD Block Diagram
16.5.1 LCD Duty
The setting of the LCD output waveform duty is dependent on the
number of backplane drivers required. Three LCD duties are available:
• Static duty — BP0 is used only
• 1/3 duty — BP0, BP1, and BP3 are used
• 1/4 duty — BP0, BP1, BP2, and BP3 are used
When the LCD driver module is enabled the backplane waveforms for
the selected duty are driven out of the backplane pins. The backplane
waveforms are periodic and are shown are shown in Figure 16-6,
Figure 16-5, and Figure 16-7.
MC68HC908LJ12 — Rev. 2.1
Freescale Semiconductor
Liquid Crystal Display Driver (LCD)
Technical Data
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