GM5110 Datasheet, PDF (37/51 Pages) List of Unclassifed Manufacturers – XGA/SXGA LCD Controller

*** Genesis Microchip Confidential ***
gm5110/20 Preliminary Data Sheet
4.11.4 Output Dithering
The Gamma LUT outputs a 10-bit value for each color channel. This value is dithered down
to either 8-bits for 24-bit per pixel panels, or 6-bits for 18-bit per pixel panels.
The benefit of dithering is that the eye tends to average neighboring pixels and a smooth
image free of contours is perceived. Dithering works by spreading the quantization error over
neighboring pixels both spatially and temporally. Two dithering algorithms are available:
random or ordered dithering. Ordered dithering is recommended when driving a 6-bit panel.
All gray scales are available on the panel output whether using 8-bit panel (dithering from 10
to 8 bits per pixel) or using 6-bit panel (dithering from 10 down to 6 bits per pixel).
4.12 Energy Spectrum Management (ESM)
High spikes in the EMI power spectrum may cause LCD monitor products to violate
emissions standards. The gm5110/20 has many features that can be used to reduce
electromagnetic interference (EMI). These include drive strength control and clock spectrum
modulation. These features help to eliminate the costs associated with EMI reducing
components and shielding.
4.13 OSD
The gm5110/20 has a fully programmable, high-quality OSD controller. The graphics are
divided into “cells” 12 by 18 pixels in size. The cells are stored in an on-chip static RAM
(4096 words by 24 bits) and can be stored as 1-bit per pixel data, 2-bit per pixel data or 4-bit
per pixel data. This permits a good compression ratio while allowing more than 16 colors in
the image.
Some general features of the gm5110/20 OSD controller include:
OSD Position – The OSD menu can be positioned anywhere on the display region. The
reference point is Horizontal and Vertical Display Background Start (DH_BKGND_START
and DV_BKGND_START in Figure 18).
OSD Stretch – The OSD image can be stretched horizontally and/or vertically by a factor of
two, three, or four. Pixel and line replication is used to stretch the image.
OSD Blending – Sixteen levels of blending are supported for the character-mapped and
bitmapped images. One host register controls the blend levels for pixels with LUT values of
128 and greater, while another host register controls the blend levels for pixels with LUT
values of 127 and lower. OSD color LUT value 0 is reserved for transparency and is
unaffected by the blend attribute.
June 2002
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C5110-DAT-01C