saa6703ah NXP Semiconductors, saa6703ah Datasheet - Page 64

• Manufacturer Part Number: saa6703ah
• Description: Xga Analog Input Flat Panel Controller.
• Manufacturer: NXP Semiconductors

Philips Semiconductors
When putting together a slider with multiple characters
(see Fig.20), a slider always consists of three basic parts:
a start part (S), a middle part (M) with different fill grades
(fg) and an ending part (E).
The start part is always located at address 1D2H
(horizontal) respectively 1F6H (vertical) and the end part is
always located at 1E3H respectively 1E4H.
The characters in between the start and the end character
correspond to different fill grades of the middle part that
are needed to give a subcharacter precision in a custom
slider. In this system the middle part uses a natural
resolution of 16 pixel per character which is resulting in
17 different characters from empty to full. If the display size
is different from the natural resolution, either some fill
grades will be skipped or some fill grades will be doubled
within the 17 characters that are reserved to represent the
middle parts. Anyhow mathematically, it is always correct
to use the slider resolution of 16 to calculate the fill grade
of the last partly filled slider part and use this value directly
to index to the correct middle part. Using this approach
results in an overall slider resolution equal to the number
of used middle characters multiplied by 16 to graphically
display any values within an OSM either with a fill bar or a
single marker.
To achieve more flexibility in the OSD look, 4 kbyte of user
definable RAM can be used in addition to the ROM/GEN
2004 Apr 01
handbook, full pagewidth
XGA analog input flat panel controller
border
S
fg = 16
M
Fig.20 Multicolour slider generation.
fg = 16
M
OSDT_FR_X
64
fg = 7
characters. This font definition RAM can contain a
downloadable mixed multicolour or single colour font
which is in terms of character size freely programmable via
OSDT_FR_X and OSDT_FR_Y registers but has to be
between 8
valid for all characters inside the RAM, no matter if they are
defined in single colour or multicolour but a single colour
pixel can be stored with one while a multicolour pixel
occupies two bits inside the font RAM. For single colour
characters a pixel of value ‘0’ will be displayed as
background and a pixel data of value ‘1’ will be displayed
as foreground according to the defined colour values in the
OSDT_PROP registers and the OSD colour definitions on
register page 9. For multicolour characters always two bits
are taken for each pixel that directly map to the four colour
value inside the selected multicolour palette which is also
defined in register page 9 and is selected within
OSDT_PROP.
The font RAM (see Table 45) can store a maximum
number of 512 8
corresponds to the 9-bit charcode in the OSDT_PROP
registers. Using multicolour definitions that need two bits
per pixel and/or larger font resolution reduces of course
the number of possible characters to be stored in the font
RAM.
M
8 and 32
fg = 0
M
8 single colour characters which
32 pixels. This font resolution is
MHC227
E
SAA6703AH
Product specification
colour 0 (BG)
colour 1 (FG)
colour 2 (FG)
colour 3 (FG)
offset
gap
OSDT_FR_Y