VSP 94x2A
DATA SHEET
2.1.6. Luminance Processing
characteristic for SECAM (4.25 MHz)
A luminance notch filter is implemented to separate
the chroma information from the luminance. Depend-
ing on the color standard, one out of three different
notch characteristics is chosen (‘PAL’, ‘NTSC’,
‘SECAM’) automatically.
5
0
NTCHSEL=
4.25
5
’100’
’001’
’000’
10
15
20
25
30
’010’
For PAL and Secam the respective notch filters have 5
different characteristics each. The luminance notch fil-
ter for NTSC can be set to 4 different filter response
curves. They can be selected by NTCHSEL. Alterna-
tively, no notch should be used for Y/C input
(NOTCHOFF). The filter characteristics can be found
in Figure 2–8. In SECAM operation, the notch filter can
be fixed to one frequency or toggle between 4.4 MHz
and 4.25 MHz depending on the transmitted color (Dr,
Db) (SECNTCH).
’011’
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
frequency [MHz]
Fig. 2–10: Filter Characteristics for SECAM
(SECNTCH=’01’, 4.25 MHz)
A simple lowpass-filter can be enabled by LPPOST to
further reduce high-frequency noise component from
the CVBS signal.
characteristic for Y/C
5
LPPOST=0
0
LPPOST=1
5
10
15
20
25
30
characteristic for NTSC
5
NTCHSEL=
3.58
’x00’
0
’x01’
’x10’
5
’x11’
10
15
20
25
30
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
frequency [MHz]
Fig. 2–11: Filter Characteristics for Y/C mode.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
The black level can be shifted by the parameter
LMOFST. This is required to compensate 7.5 IRE off-
sets in some input signals (e.g. NTSC) The positive or
negative offset is added to the Y signal before scaling.
frequency [MHz]
Fig. 2–8: Filter Characteristics for NTSC, PAL M and
PAL N
BLACK
BLANKING BLACK
BLANKING
LMOFST='10'
LMOFST='00'
LMOFST='11'
LMOFST='10'
LMOFST='00'
LMOFST='11'
characteristic for PAL
5
NTCHSEL=
4.43
LMOFST='01'
0
5
’000’
’100’
LMOFST='01'
Input signals without 7.5IRE offset
Input signals with 7.5IRE offset
10
15
20
25
30
’010’
Fig. 2–12: Adjustment of ‘Black’ to ‘Blankingvalue’ at
Analog Output.
’011’
’001’
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
frequency [MHz]
Fig. 2–9: Filter Characteristics for PAL B/G, NTSC44,
PAL60
12
Aug. 16, 2004; 6251-552-1DS
Micronas
MICRONAS [ MICRONAS ]
