Datasheet

 2010-2011 Microchip Technology Inc. DS39996F-page 265
PIC24FJ128GA310 FAMILY
21.0 LIQUID CRYSTAL DISPLAY
(LCD) CONTROLLER
The Liquid Crystal Display (LCD) Controller generates
the data and timing control required to directly drive a
static or multiplexed LCD panel. In 100-pin devices
(PIC24FJXXXGA310), the module can drive panels of
up to eight commons and up to 60 segments when 5 to
8 commons are used, or up to 64 segments when 1 to
4 commons are used.
The module has these features:
• Direct driving of LCD panel
• Three LCD clock sources with selectable prescaler
• Up to eight commons:
- Static (One common)
- 1/2 multiplex (two commons)
- 1/3 multiplex (three commons)
- 1/8 multiplex (eight commons)
• Ability to drive from 30 (in 64-pin devices) to
64 (100-pin) segments, depending on the
Multiplexing mode selected
• Static, 1/2 or 1/3 LCD bias
• On-chip bias generator with dedicated charge
pump to support a range of fixed and variable bias
options
• Internal resistors for bias voltage generation
• Software contrast control for LCD using internal
biasing
A simplified block diagram of the module is shown in
Figure 21-1.
FIGURE 21-1: LCD CONTROLLER MODULE BLOCK DIAGRAM
Note: This data sheet summarizes the features of
this group of PIC24F devices. It is not
intended to be a comprehensive reference
source. For more information, refer to the
“PIC24F Family Reference Manual”,
Section 52. “Liquid Crystal Display
(LCD)” (DS39740). The information in this
data sheet supersedes the information in
the FRM.
COM<7:0>
Timing Control
Data Bus
SOSC
FRC Oscillator
LPRC Oscillator
512
to
64
MUX
SEG<63:0>
To I/O Pins
32 x 16 (= 8 x 64)
LCD DATA
LCDCON
LCDPS
LCDSEx
LCDDATA0
LCDDATA1
LCDDATA30
LCDDATA31
.
.
.
LCD Bias Generation
LCD Clock
Source Select
LCD
Charge Pump
64
8
Bias
Voltage
16
(Secondary Oscillator)
Resistor Ladder
LCDREF
LCDREG