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SAM4L Datasheet, PDF (1027/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU | |||
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ATSAM4L4/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 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.
Figure 39-1. LCD Segment/Common Terminals
SEG0
SEG1
SEG2
COM0
...
COM1
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 the âWAITâ Power Save Mode.
42023CâSAMâ02/2013
1027
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