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HD64645/HD64646
LCTC (LCD Timing Controller)
ADE-207-276(Z)
'99.9
Rev. 0.0
Description
The HD64645/HD64646 LCTC is a control LSI for large size dot matrix liquid crystal displays. The LCTC
is software compatible with the HD6845 CRTC, since its programming method of internal registers and
memory addresses is based on the CRTC. A display system can be easily converted from a CRT to an
LCD.
The HD64646 LCTC is a modified version of the HD64645 LCTC with different LCD interface timing.
The LCTC offers a variety of functions and performance features such as vertical and horizontal scrolling,
and various types of character attribute functions such as reverse video, blinking, nondisplay (white or
black), and an OR function for simple superimposition of character and graphic displays. The LCTC also
provides DRAM refresh address output.
A compact LCD system with a large screen can be configured by connecting the LCTC with the
HD66110ST (column driver) and the HD66113T (common driver) by utilizing 4-bit
×
2 data outputs.
Power dissipation has been lowered by adopting the CMOS process.
Features
Software compatible with the HD6845 CRTC
Programmable screen size
Up to 1024 dots (height)
Up to 4096 dots (width)
High-speed data transfer
Up to 20 Mbits/s in character mode
Up to 40 Mbits/s in graphic mode
Selectable single or dual screen configuration
Programmable multiplexing duty ratio: static to 1/512 duty cycle
Programmable character font
1-32 dots (height)
8 dots (width)