Datasheet

 2009-2011 Microchip Technology Inc. DS39957D-page 273
PIC18F87K90 FAMILY
20.0 LIQUID CRYSTAL DISPLAY
(LCD) DRIVER MODULE
The Liquid Crystal Display (LCD) driver module
generates the timing control to drive a static or
multiplexed LCD panel. In the 80-pin devices
(PIC18F8XK90), the module drives the panels of up to
four commons and up to 48 segments and in the 64-pin
devices (PIC18F6XK90), the module drives the panels
of up to four commons and up to 33 segments. It also
provides control of the LCD pixel data.
The LCD driver module supports:
• Direct driving of LCD panel
• Three LCD clock sources with selectable prescaler
• Up to four commons:
- Static (One common)
- 1/2 multiplex (two commons)
- 1/3 multiplex (three commons)
- 1/4 multiplex (four commons)
• Up to 48 (in 80-pin devices), 32 (in 64-pin
devices) segments
• Static, 1/2 or 1/3 LCD bias
• Internal resistors for bias voltage generation
• Software contrast control for LCD using the
internal biasing
A simplified block diagram of the module is shown in
Figure 20-1.
FIGURE 20-1: LCD DRIVER MODULE BLOCK DIAGRAM
COM<3:0>
Clock Source
Timing Control
Data Bus
Select and
Prescaler
LF-INTOSC Oscillator
FOSC/4
SOSC
192-to-48
MUX
SE<47:0>
To I/O Pads
To I/O Pads
24 x 8
(= 4 x 48)
LCDDATAx
Registers
LCDCON
LCDPS
LCDSEx