ST92196A STMicroelectronics, ST92196A Datasheet - Page 144

• Manufacturer Part Number: ST92196A
• Description: 8/16-bit Mcu For Tv Applications With Up To 96k Rom, On-screen-display And 1 Or 2 Data Slicers
• Manufacturer: STMicroelectronics

OSD CONTROLLER (Cont’d)
Bit 1 = ROU Rounding control bit
This bit enables or disables the rounding for the
whole row.
0: the rounding is disabled
1: the rounding is enabled
Note: For a 18x26 matrix size, there is no rounding
when the character size is (1X,1Y). For any other
(X,Y) size combinations, the rounding is possible
for the 18x26 font matrix.
Bit 0 = FR Fringe control bit
This bit enables or disables the fringe for the whole
row. The fringe mechanism can be activated for
any size and matrix format.
0: the character fringe is disabled
1: the character fringe is enabled.
Note: In case of fringe usage in 1Y vertical size
and interlaced mode, a flicker may appear on
screen as the fringe information is built on a field
basis.
8.5.8.4 Active Range
Address in Segment 22h: 2p + 5. See
The active range feature is useful for software con-
trolled smooth vertical scrolling (up or down).
For each row to be displayed, the first line (RS)
and the last line (RE) to be displayed for the cur-
rent row have to be specified.
The two values (RS[3:0] and RE[3:0]) are com-
pared to the row line counter value. If the value of
the counter is outside the active range (less than
RS[3:0] or greater than or equal to RE[3:0]), the
border color is displayed as defined by its at-
tributes. Otherwise, if the counter value is inside
RS3
7
RS2
RS1
RS0
RE3
RE2
Figure
RE1
59.
RE0
0
- ON SCREEN DISPLAY CONTROLLER (OSD)
the active range, the normal character pixel
processing and display is done (See
Let’s assume that the start address of the current
row buffer is 2p (even address).
Bits 7:4 = RS[3:0] Active Range Start value
The RS[3:0] value range is 0h-Ch (0-12) in all cas-
es (9x13 or 18x26 character matrix).
Bits 3:0 = RE[3:0] Active Range End value
The RE[3:0] value range is 1h-Dh (1-13) in all cas-
es (9x13 or 18x26 character matrix).
Note: For 18x26 matrix characters, the active
range is calculated by pair of TV lines, i.e. the ac-
tive range always starts on the first field and finish-
es on the second field (in interlaced mode).
In case of non-interlaced display mode, the active
range is calculated by pair of TV lines.
Figure 66. Active Range Example
RS = 0 ; RE = 13
ACTIVE RANGE EXAMPLE
10
11
12
9
0
1
2
3
4
5
6
7
8
RS = 4 ; RE = 9
Pixel not
displayed
Figure
144/268
66).