MC68HC908LJ12CPB FREESCALE [Freescale Semiconductor, Inc], MC68HC908LJ12CPB Datasheet - Page 322

• Manufacturer Part Number: MC68HC908LJ12CPB
• Description: 8-bit microcontroller units
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

16.5.2 LCD Voltages (V
16.5.3 LCD Cycle Frame
MC68HC908LJ12
Freescale Semiconductor
—
Rev. 2.1
The voltage V
are internal bias voltages for the LCD driver waveforms. They are
derived from V
The relative potential of the LCD voltages are:
The V
bits, LCCON[2:0].
The LCD driver module uses the CGMXCLK (see
(OSC)) as the input reference clock. This clock is divided to produce the
LCD waveform base clock, LCDCLK, by configuring the LCLK[2:0] bits
in the LCD clock register. The LCDCLK clocks the backplane and the
frontplane output waveforms.
The LCD cycle frame is determined by the equation:
For example, for 1/3 duty and 256Hz waveform base clock:
LCD,
•
•
•
•
LCD3
V
V
V
V
V
LCD CYCLE FRAME =
LCD1,
LCD
LCD1
LCD2
LCD3
LCD CYCLE FRAME =
Liquid Crystal Display Driver (LCD)
bias voltage, V
= V
= 2/3 × (V
= 1/3 × (V
= V
V
LCD
LCD2
LCD
DD
bias
is connected directly to V
using a resistor ladder (see
, V
LCD3
LCD
LCD
bias
= 11.72 ms
)
– V
– V
LCD WAVEFORM BASE CLOCK × DUTY
256 × (1/3)
, is controlled by the LCD contrast control
bias
bias
1
)
)
Liquid Crystal Display Driver (LCD)
DD
. V
1
Figure
LCD1
Section 7. Oscillator
, V
16-3).
LCD2
Technical Data
, and V
LCD3
323