TDA935x Philips, TDA935x Datasheet - Page 52

• Manufacturer Part Number: TDA935x
• Description: TV Signal Processor-Teletext Decoder with Embedded u-Controller
• Manufacturer: Philips

Philips Semiconductors
values 00h to 03h for TAS<5:0> will result in a corrupted
display.
The width of the text area is defined in REG4:Text Area
End by setting the end character value TAE<5:0>. This
number determines where the background colour of the
Text Area will end if set to extend to the end of the row. It
will also terminate the character fetch process thus
eliminating the necessity of a row end attribute. This
entails however writing to all positions.
The vertical offset is set in REG1:Text Position Vertical
Register. The offset value VOL<5:0> is done in number of
TV scan lines.
NOTE: REG1:Text Position Vertical Register should not
be set to 00 Hex as the Display Busy interrupt is not
generated in these circumstances.
Character Set
To facilitate the global nature of the device the character
set has the ability to accommodate a large number of
characters, which can be stored in different matrices.
C
The character matrices that can be accommodated are: -
(HxVxPlanes) 12x9x1, 12x10x1, 12x13x1, 12x16x1.
These modes allow two colours per character position.
In CC mode two additional character matrices are
available to allow four colours per character: -
(HxVxPlanes) 12x13x2, 12x16x2.
The characters are stored physically in ROM in a matrix of
size either 12x10 or 12x16.
C
Four character sets are available in the device. A set can
consist of alphanumeric characters as required by the
WST Teletext or FCC 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 TXT18.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>.
2001 Jan 18
HARACTER
HARACTER
TV signal processor-Teletext decoder with
embedded -Controller
M
S
ET
ATRICES
S
ELECTION
52
ROM A
Three ROM’s are used to generate the correct pixel
information. The first contains the National Option look-up
table, the second contains the Basic Character look-up
table and the third contains the Character Pixel
information. Although these are individual ROM, since
they do not need to be accessed simultaneously they are
all combined into a single ROM unit.
DDRESSING
Approx. 710 Text
430Text +176CC
TDA935X/6X/8X PS/N2 series
CHAR PIXEL
DATA
71680 x 12 bits
LOOK-UP
Basic + Nat Opt
2048 location
or
Fig.24 ROM Organisation
2400H
0800H
0000H
Tentative Device Specification
Look-Up Set 0
Look-Up Set3
Look-Up Set2
Look-Up Set1
0800
0600
0400
0200
0000