MC68HC908LJ12 Datasheet, PDF (325/413 Pages) Freescale Semiconductor, Inc – 8-bit microcontroller units

Liquid Crystal Display Driver (LCD)
16.7 I/O Signals
The LCD driver module has thirty (30) output pins and shares eight of
them with port C I/O pins.
• FP0/BP3 (multiplexed; selected as FP0 or BP3 by DUTY[1:0])
• BP0–BP2
• FP1–FP26 (FP19–FP26 shared with port C)
16.7.1 BP0–BP3 (Backplane Drivers)
BP0–BP3 are the backplane driver output pins. These are connected to
the backplane of the LCD panel. Depending on the LCD duty selected,
the voltage waveforms in Figure 16-6, Figure 16-5, and Figure 16-7
appear on the backplane pins.
BP3 pin is only used when 1/4 duty is selected. The pin becomes FP0
for static and 1/3 duty operations.
DUTY = 1/3
BP0
1FRAME
V_LCD
V_LCD1
V_LCD2
V_LCD3
V_LCD
BP1
V_LCD1
V_LCD2
V_LCD3
BP2
NOTES:
1. BP3 is not used.
2. At 1/3 duty, 1FRAME has three times the cycle of LCD waveform base clock.
V_LCD
V_LCD1
V_LCD2
V_LCD3
Figure 16-5. 1/3 Duty LCD Backplane Driver Waveforms
Technical Data
326
Liquid Crystal Display Driver (LCD)
MC68HC908LJ12 — Rev. 2.1
Freescale Semiconductor