SAA5500PS Philips Semiconductors, SAA5500PS Datasheet - Page 53

• Manufacturer Part Number: SAA5500PS
• Description: Standard TV Microcontrollers with On-Screen Display(OSD)
• Manufacturer: Philips Semiconductors

Philips Semiconductors
19.2
The display is configured as WST with additional serial and
global attributes. The display is configured as a fixed
25 rows with 40 characters per row.
19.3
19.3.1
Flashing causes the foreground colour pixel to be
displayed as the background pixels.The flash frequency is
controlled by software setting and resetting the MMR
Status (see Table 24) at the appropriate interval.
This attribute is set by the control character ‘flash’ (08H)
(see Fig.26) and remains valid until the end of the row or
until reset by the control character ‘steady’ (09H).
19.3.2
Two types of boxes exist, the Teletext box and the
OSD box. The Teletext box is activated by the ‘start box’
control character (0BH), two start box characters are
required to begin a Teletext box, with the box starting
between the two characters. The box ends at the end of
the line or after a ‘end box’ control character.
OSD boxes are started using size implying OSD control
characters (BCH, BDH, BEH and BFH). The box starts
after the control character (‘set after’) and ends either at
the end of the row or at the next size implying OSD
character (‘set at’). The attributes flash, Teletext box,
conceal, separate graphics, twist and hold graphics are all
reset at the start of an OSD box, as they are at the start of
the row. OSD boxes are only valid in TV mode which is
defined by TXT5 = 03H and TXT6 = 03H.
19.3.3
The size of the characters can be modified in both the
horizontal and vertical directions.
Three horizontal sizes are available normal ( 1),
double ( 2), quadruple ( 4). The control characters
‘normal size’ (0CH/BCH) enables normal size, the ‘double
width’ or ‘double size’ (0EH/BEH/0FH/BFH) enables
double width characters.
1999 Oct 27
Standard TV microcontrollers with
On-Screen Display (OSD)
Display mode
Display feature descriptions
F
B
S
LASH
OXES
IZE
53
Any two consecutive combination of ‘double width’ or
‘double size’ (0EH/BEH/0FH/BFH) activates quadruple
width characters, provided quadruple width characters are
enabled by TXT4.QUAD WIDTH ENABLE.
Three vertical sizes are available normal ( 1), double ( 2),
quadruple ( 4). The control characters ‘normal size’
(0CH/BCH) enable normal size, the ‘double height’ or
‘double size’ (0DH/BDH/0FH/BFH) enable double height
characters. Quadruple height characters are achieved by
using double height characters and setting the global
attributes TXT7.DOUBLE HEIGHT (expand) and
TXT7.BOTTOM/TOP.
If double height characters are used in Teletext mode,
single height characters in the lower row of the double
height character are automatically disabled.
19.3.4
19.3.4.1
A CLUT with 16 colour entries is provided. The colours are
programmable out of a palette of 4096 (4 bits per
R, G and B). The CLUT is defined by writing data to a RAM
that resides in the MOVX address space of the 80C51.
Table 14 CLUT colour values
19.3.5
The foreground colour is selected via a control character
(see Fig.26). The colour control characters take effect at
the start of the next character (set-after) and remain valid
until the end of the row, or until modified by a control
character. Only 8 foreground colours are available.
The TEXT foreground control characters map to the CLUT
entries as shown in Table 15.
(B11 TO B8)
RED<3:0>
0000
0000
1111
1111
...
C
F
OREGROUND
OLOURS
Colour Look Up Table (CLUT)
(B7 TO B4)
GRN<3:0>
0000
0000
1111
1111
...
C
OLOUR
BLUE<3:0>
(B3 TO B0)
Preliminary specification
0000
1111
0000
1111
...
SAA55xx
COLOUR
ENTRY
14
15
...
0
1