Microchip Technology MA180025 データシート

ページ / 450
 2010 Microchip Technology Inc.
DS39933D-page 183
PIC18F87J90 FAMILY
17.0 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. It also provides control of the
LCD pixel data. The module can drive panels of up to
192 pixels (48 segments by 4 commons) in
PIC18F8XJ90 devices and 132 pixels (33 segments by
4 commons) in PIC18F6XJ90 devices. 
The LCD driver module supports these features:
• Direct driving of LCD panel
• On-chip bias generator with dedicated charge 
pump to support a range of fixed and variable bias 
options
• Up to four commons, with four Multiplexing modes
• Up to 48 (PIC18F8XJ90 devices) or 33 
(PIC18F6XJ90 devices) segments
• Three LCD clock sources with selectable prescaler, 
with a fourth source available for use with the LCD 
charge pump
A simplified block diagram of the module is shown in
Figure 17-1.
FIGURE 17-1:
LCD DRIVER MODULE BLOCK DIAGRAM
COM<3:0>
Timing Control
Data Bus
INTRC Oscillator
F
OSC
/4
T13CKI
192
to
48
MUX
SEG<47:0>
To I/O Pins
24 x 8 (= 4 x 48)
LCD DATA
LCDCON
LCDPS
LCDSEx
LCDDATA0
LCDDATA1
LCDDATA22
LCDDATA23
..
.
LCD Bias Generation
LCD Clock
Source Select
LCD
Charge Pump
48
4
Bias
Voltage
8
INTOSC Oscillator