Atmel SAM4L Xplained Pro Evaluation Kit Atmel ATSAM4L-XPRO ATSAM4L-XPRO Data Sheet
Product codes
ATSAM4L-XPRO
1032
42023E–SAM–07/2013
ATSAM4L8/L4/L2
39. LCD Controller (LCDCA)
Rev: 1.0.0.0
39.1
Features
•
Display capacity up to 40 segment and up to 4 common terminals
•
Supports from static up to 1/4 duty
•
Supports static and 1/3 bias
•
Shadow display memory gives full freedom in segment update
•
ASCII character mapping
•
Automated characters string scrolling
•
Automated characters string display
•
Automated segments display
•
Autonomous animation up to 8 segments
•
LCD driver active in power save mode for low power operation
•
Low power waveform
•
Flexible selection of frame frequency
•
Configurable blink mode and frequency
•
Uses only 32 kHz clock
•
On-chip LCD power supply
•
Software contrast adjustment control
•
Equal source and sink capability to increase LCD life time
•
Interrupt mode for display update or wake-up from sleep mode
39.2
Overview
A LCD display is made of several segments (or complete symbols) which can be visible or invis-
ible. A segment has two electrodes with liquid crystal between them. These electrodes are the
common terminal (COM) and the segment terminal (SEG). When a voltage above a threshold
voltage is applied across the liquid crystal, the segment becomes visible. The voltage must alter-
nate to avoid an electrophoresis effect in the liquid crystal, this effect degrades the display.
Hence the voltage waveform across a segment must not have a DC-component.
ible. A segment has two electrodes with liquid crystal between them. These electrodes are the
common terminal (COM) and the segment terminal (SEG). When a voltage above a threshold
voltage is applied across the liquid crystal, the segment becomes visible. The voltage must alter-
nate to avoid an electrophoresis effect in the liquid crystal, this effect degrades the display.
Hence the voltage waveform across a segment must not have a DC-component.
Figure 39-1. LCD Segment/Common Terminals
The LCD controller (LCDCA) is intended for monochrome passive liquid crystal display (LCD)
with up to 4 common terminals and up to 40 segment terminals. Unused segment/common ter-
minals (pins) are configured as general purpose I/O pins.The LCD controller uses a 32kHz clock
(CLK_LCD) and can therefore be running in deep sleep modes.
with up to 4 common terminals and up to 40 segment terminals. Unused segment/common ter-
minals (pins) are configured as general purpose I/O pins.The LCD controller uses a 32kHz clock
(CLK_LCD) and can therefore be running in deep sleep modes.
segm
ent
0
se
gm
en
t 1
segm
en
t 2
seg
me
nt
4
2
segm
en
t 41
se
gm
en
t 40
COM0
COM1
SEG0
SEG1
SEG2
...
..
.