1999 May 31
22
Philips Semiconductors
Product specication
Digital video encoder
SAA7126H; SAA7127H
Table 40 Subaddress 75H
Table 41 Subaddresses 76H, 77H and 7CH
Table 42 Subaddresses 78H, 79H and 7CH
Table 43 Subaddress 7CH
Table 44 Subaddresses 7AH to 7CH
DATA BYTE
DESCRIPTION
VS_S
vertical sync shift between RCV1 and RCV2 (switched to output); in master mode it is possible to shift
H-sync (RCV2; CBLF = 0) against V-sync (RCV1; SRCV1 = 00)
standard value: VS_S = 3
CSYNCA
advanced composite sync against RGB output from 0LLC to 31LLC
DATA BYTE
DESCRIPTION
REMARKS
TTXOVS
rst line of occurrence of signal on pin TTXRQ in odd eld
PAL: TTXOVS = 05H;
NTSC: TTXOVS = 06H
line = (TTXOVS + 4) for M-systems
line = (TTXOVS + 1) for other systems
TTXOVE
last line of occurrence of signal on pin TTXRQ in odd eld
PAL: TTXOVE = 16H;
NTSC: TTXOVE = 10H
line = (TTXOVE + 3) for M-systems
line = TTXOVE for other systems
DATA BYTE
DESCRIPTION
REMARKS
TTXEVS
rst line of occurrence of signal on pin TTXRQ in even eld
PAL: TTXEVS = 04H;
NTSC: TTXEVS = 05H
line = (TTXEVS + 4) for M-systems
line = (TTXEVS + 1) for other systems
TTXEVE
last line of occurrence of signal on pin TTXRQ in even eld
PAL: TTXEVS = 16H;
NTSC: TTXEVS = 10H
line = (TTXEVE + 3) for M-systems
line = TTXEVE for other systems
DATA BYTE
LOGIC
LEVEL
DESCRIPTION
TTXO
0
new TTX protocol selected: at each rising edge of TTXRQ a single TTX bit is requested
see Fig.14; default after reset
1
old TTX protocol selected: the encoder provides a window of TTXRQ going HIGH; the
length of the window depends on the chosen TTX standard see Fig.14
TTX60
0
enables NABTS (FISE = 1) or European TTX (FISE = 0); default after reset
1
enables world standard teletext 60 Hz (FISE = 1)
DATA BYTE
DESCRIPTION
FAL
rst active line = FAL + 4 for M-systems, = FAL + 1 for other systems, measured in lines
FAL = 0 coincides with the rst eld synchronization pulse
LAL
last active line = LAL + 3 for M-systems, = LAL for other system, measured in lines
LAL = 0 coincides with the rst eld synchronization pulse