mc68hc05l28 Freescale Semiconductor, Inc, mc68hc05l28 Datasheet - Page 73

• Manufacturer Part Number: mc68hc05l28
• Description: ?exible General-purpose Microcomputer
• Manufacturer: Freescale Semiconductor, Inc

LIQUID CRYSTAL DISPLAY DRIVER MODULE
This chapter describes the generic M68HC05 family LCD driver module. Any differences in the
module specific to the MC68HC05L28 are indicated along with the generic description.
The M68HC05 family LCD driver module can be configured with up to 24 frontplane drivers and a
maximum of 4 backplane drivers. This allows a maximum of 96 LCD segments.
The LCD driver module on the MC68HC05L28 supports 18 frontplanes and 4 backplanes, allowing
a maximum of 72 LCD segments. Each segment is controlled by a corresponding bit in the LCD
RAM. The mode of operation is determined by the values set in the LCD control register at $1E.
At reset or on power-up, the drivers are configured in the default duplex mode, 1/2 bias with 2
backplanes and 18 frontplanes. Also at power-up or reset the ON/OFF control for the display, the
DISON bit in the LCD control (LCD) register, is cleared disabling the LCD drivers. Figure 7-1 shows
a block diagram of the LCD system.
MC68HC05L28
Internal
signals
Internal data bus
Internal address bus
LIQUID CRYSTAL DISPLAY DRIVER MODULE
Control
logic
Figure 7-1 LCD system block diagram
13
FP17
Segment
8
driver
RAM
LCD
7
FP0
Backplane
generator
Voltage
driver
BP3
BP2
BP1
BP0
V
LCD
MOTOROLA
TPG
7-1
7