saa569x NXP Semiconductors, saa569x Datasheet - Page 64

• Manufacturer Part Number: saa569x
• Description: Enhanced Tv Microcontrollers With On-screen Display Osd
• Manufacturer: NXP Semiconductors

Philips Semiconductors
The tabulation bit is also used with extension packets.
The first eight data bytes of packet X/1/24 are used to
extend the Fastext prompt row to 40 characters. These
characters are written into whichever part of the memory
the packet 24 is being written into (determined by the
‘X24 POSN’ bit).
Packets X/0/27/0 contain five Fastext page links and the
link control byte. They are captured, Hamming checked
and stored in the same way as are packets X/27/0 in
625-line text. Packets X/1/27/0 are not captured.
Because there are only two magazine bits in 525-line text,
packets with the magazine bits all set to a logic 0 are
referred to as being in magazine 4. Therefore, the
broadcast service data packet is packet 4/30, rather than
packet 8/30.
2002 May 06
handbook, full pagewidth
Enhanced TV microcontrollers with
On-Screen Display (OSD)
(1) If X24 POSN bit = 1.
(2) Byte 10 reserved.
Row 0
10
11
12
13
14
15
16
17
18
19
21
20
22
23
24
25
1
2
3
4
5
6
7
8
9
0
0
OSD only
Control Data
Fig.23 Packet storage locations, 525-line.
6
aw/ag
7
8
9
10
(2)
Packet X/0/0
Packet X/0/1
Packet X/0/2
Packet X/0/3
Packet X/0/4
Packet X/0/5
Packet X/0/6
Packet X/0/7
Packet X/0/8
Packet X/0/9
Packet X/0/10
Packet X/0/11
Packet X/0/12
Packet X/0/13
Packet X/0/14
Packet X/0/15
Packet X/0/16
Packet X/0/17
Packet X/0/18
Packet X/0/19
Packet X/0/20
Packet X/0/21
Packet X/0/22
Packet X/0/23
Packet X/0/24
64
As in 625-line text, the first 20 bytes of packet 4/30 contain
encoded data that is decoded in the same way as in
packet 8/30. The last 12 bytes of the packet contains half
of the parity encoded status message. Packet 4/0/30
contains the first half of the message and packet 4/1/30
contains the second half. The last four bytes of the
message are not written into memory. The first 20 bytes of
the each version of the packet are the same, so they are
stored whenever either version of the packet is acquired.
In 525-line text, each packet 26 only contains ten 24/18
Hamming encoded data triplets, rather than the 13 found
in 625-line text. The tabulation bit is used as an extra bit
(the MSB) of the designation code, allowing 32 packet 26s
to be transmitted for each page. The last byte of each
packet 26 is ignored.
23
(1)
Packet X/1 /24
Packet X/1/12
Packet X/1/16
Packet X/1/20
Packet X/1/1
Packet X/1/4
Packet X/1/8
Rolling time
GSA004
SAA567x; SAA569x
(1)
39
Objective specification