
2000 Feb 23
61
Philips Semiconductors
Preliminary specification
TV microcontrollers with Closed Captioning (CC)
and On-Screen Display (OSD)
SAA55xx
18.8.2
C
HARACTER SET SELECTION
Four character sets are available in the device. A set can
consist of alphanumeric characters as required by the
WST or US Closed Captioning, Customer definable
On-Screen Display characters, and Special Graphic
characters.
CC:
Only a single character set can be used for display
and this is selected using the Basic Set selection
TXT18.BS<1:0>. When selecting a character set in
CC mode, the Twist Set selection TXT19.TS<1:0> should
be set to the same value as TXT18.BS<1:0> for correct
operation.
TXT:
Two character sets can be displayed at once. These
are the basic G0 set or the alternative G0 set (Twist Set).
The basic set is selected using TXT18.BS<1:0>.
The alternative/twist character set is defined by
TXT19.TS<1:0>. Since the alternative character set is an
option it can be enabled or disabled using TXT19.TEN,
and the language code that is defined for the alternative
set is defined by TXT19.TC<2:0>.
The National option table is selected using
TXT18.NOT<3:0>. A maximum of 31 National option
tables can be defined when combined with the
EAST/WEST control bit located in register TXT4.
An example of the character set selection and definitions
is show in Table 22.
AnexampleoftheNationaloptionreferencetableisshown
in Table 23. Only a certain number of national options will
be relevant for each of the Character sets.
Table 22
Character set selection
Table 23
National option selection
BS1/TS1
BS0/TS0
CHARACTER SET
EXAMPLE LANGUAGE
0
0
1
1
0
1
0
1
Set 0
Set 1
Set 2
Set 3
Latin
Greek
Closed Caption
C12
0
0
0
0
1
1
1
1
C13
0
0
1
1
0
0
1
1
C14
0
1
0
1
0
1
0
1
NOT<3:0> = 0000 NOT<3:0> = 0001 NOT<3:0> = 0010
English
Polish
German
German
Swedish
Swedish
Italian
Italian
French
French
Spanish
Czech
Czech
...
...
...
...
...
...
...
...
...
NOT<3:0> = 1110
Polish
German
Estonian
Lettish
Russian
Serb-Croat
Czech
English
German
Swedish
Italian
French
Spanish
Turkish