
2000 Mar 08
35
Philips Semiconductors
Product specication
Digital video encoder
SAA7128H; SAA7129H
Table 71 Subaddress 7BH
Table 72 Subaddress 7CH
Table 73 Subaddress 7EH
Table 74 Subaddress 7FH
BIT
SYMBOL
DESCRIPTION
7 to 0
LAL[7:0]
These are the 8 LSBs of the 9-bit code that determines the last active line. The MSB is
held in subaddress 7CH, see Table 72. LAL[8:0] = 0 coincides with the rst eld
synchronization pulse.
last active line = LAL[8:0] + 3 for M-systems
last active line = LAL[8:0] for other systems
BIT
SYMBOL
DESCRIPTION
7
TTX60
0 = enables NABTS (FISE = 1) or European teletext (FISE = 0); default state after
reset
1 = enables World Standard Teletext 60 Hz (FISE = 1)
6
LAL8
MSB of the last active line code; see Table 71.
5
TTXO
0 = new teletext protocol selected: at each rising edge of TTXRQ a single teletext bit is
requested (see Fig.23); default state after reset
1 = old teletext protocol selected: the encoder provides a window of TTXRQ going
HIGH; the length of the window depends on the chosen teletext standard (see Fig.23)
4
FAL8
MSB of the rst active line code; see Table 70.
3
TTXEVE8
MSB of the 9-bit code that selects the last line of occurrence of signal on pin TTXRQ in
even eld; see Table 69.
2
TTXOVE8
MSB of the 9-bit code that selects the last line of occurrence of signal on pin TTXRQ in
odd eld; see Table 67.
1
TTXEVS8
MSB of the 9-bit code that selects the rst line of occurrence of signal on pin TTXRQ in
even eld; see Table 68.
0
TTXOVS8
MSB of the 9-bit code that selects the rst line of occurrence of signal on pin TTXRQ in
odd eld; see Table 66.
BIT
SYMBOL
DESCRIPTION
7 to 0
LINE[12:5]
Individual lines in both elds (PAL counting) can be disabled for insertion of teletext by
effective only, if the lines are enabled by TTXOVS/TTXOVE and TTXEVS/TTXEVE.
SYMBOL
DESCRIPTION
7 to 0
LINE[20:13]
Individual lines in both elds (PAL counting) can be disabled for insertion of teletext by
the respective LINE bits. Disabled line = LINEnn (50 Hz eld rate). This bit mask is
effective only, if the lines are enabled by TTXOVS/TTXOVE and TTXEVS/TTXEVE.