1999 May 31
19
Philips Semiconductors
Product specification
Digital video encoder
SAA7126H; SAA7127H
Table 27
Subaddress 6BH
Table 28
Logic levels and function of SRCV1
Table 29
Subaddresses 6CH and 6DH
DATA BYTE
LOGIC
LEVEL
DESCRIPTION
PRCV2
0
polarity of RCV2 as output is active HIGH, rising edge is taken when input, respectively;
default after reset
polarity of RCV2 as output is active LOW, falling edge is taken when input, respectively
pin RCV2 is switched to input; default after reset
pin RCV2 is switched to output
If ORCV2 = HIGH, pin RCV2 provides an HREF signal (horizontal reference pulse that is
defined by RCV2S and RCV2E, also during vertical blanking interval); default after reset.
If ORCV2 = LOW and bit SYMP = LOW, the signal input to RCV2 is used for horizontal
synchronization only (if TRCV2 = 1); default after reset.
If ORCV2 = HIGH, pin RCV2 provides a ‘composite-blanking-not’ signal, for example a
reference pulse that is defined by RCV2S and RCV2E, excluding vertical blanking interval,
which is defined by FAL and LAL. If ORCV2 = LOW and bit SYMP = LOW, the signal input
to RCV2 is used for horizontal synchronization (if TRCV2 = 1) and as an internal blanking
signal.
polarity of RCV1 as output is active HIGH, rising edge is taken when input; default after
reset
polarity of RCV1 as output is active LOW, falling edge is taken when input
pin RCV1 is switched to input; default after reset
pin RCV1 is switched to output
horizontal synchronization is taken from RCV1 port (at bit SYMP = LOW) or from decoded
frame sync of “CCIR 656”input (at bit SYMP = HIGH); default after reset
horizontal synchronization is taken from RCV2 port (at bit SYMP = LOW)
defines signal type on pin RCV1; see Table 28
1
0
1
0
ORCV2
CBLF
1
PRCV1
0
1
0
1
0
ORCV1
TRCV2
1
SRCV1
DATA BYTE
AS OUTPUT
AS INPUT
FUNCTION
SRCV11
SRCV10
0
0
1
0
1
0
VS
FS
VS
FS
vertical sync each field; default after reset
frame sync (odd/even)
field sequence, vertical sync every fourth field (PAL = 0)
or eighth field (PAL = 1)
FSEQ
FSEQ
1
1
not applicable
not applicable
DATA BYTE
DESCRIPTION
HTRIG
sets the horizontal trigger phase related to signal on RCV1 or RCV2 input
values above 1715 (FISE = 1) or 1727 (FISE = 0) are not allowed; increasing HTRIG
decreases delays of all internally generated timing signals; reference mark: analog output
horizontal sync (leading slope) coincides with active edge of RCV used for triggering at
HTRIG = 39H