Datasheet

© 2007 Microchip Technology Inc. DS39629C-page 257
PIC18F6390/6490/8390/8490
22.0 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
(PIC18F8390/8490), the module drives the panels of
up to four commons and up to 48 segments and in the
64-pin devices (PIC18F6390/6490), the module drives
the panels of up to four commons and up to
32 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
- 1/2 multiplex
- 1/3 multiplex
- 1/4 multiplex
• Up to 48 (in 80-pin devices)/32 (in 64-pin devices)
segments
• Static, 1/2 or 1/3 LCD bias
A simplified block diagram of the module is shown in
Figure 22-1.
FIGURE 22-1: LCD DRIVER MODULE BLOCK DIAGRAM
COM3:COM0
Clock Source
Timing Control
Data Bus
Select and
Prescaler
INTRC Oscillator
FOSC/4
T13CKI
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