VPC 323xD, VPC 324xD
ADVANCE INFORMATION
Table 2–7: Output signals corresponding to the different formats
Format
16 bit
dblclk
enable656
HSync
VSync
AVO
Y-Data
C-Data
4:2:2
0
1
1
0
PAL/NTSC
PAL/NTSC
marks active 4:2:2
pixels
YCrCb422
8 bit
YCrCb422
0
1
PAL/NTSC
not used
PAL/NTSC
not used
marks active 4:2:2
pixels
tristated
ITU-R 656
not used
ITU-R 656 tristated
The multiplex of luminance and chrominance informa-
tion and the embedding of 656-headers can be
enabled independently. An overview of the resulting
output formats and the corresponding signals is given
in Table 2–7.
2.10. PAL+ Support
For PAL+, the VPC 323xD provides basic helper pre-
processing:
– A/D conversion (shared with the existing ADCs)
– mixing with subcarrier frequency
– lowpass filter 2.5 MHz
2.9.7. Output Code Levels
Output Code Levels correspond to ITU-R code levels:
– gain control by chroma ACC
Y = 16...240
Black Level = 16
CrCb = 128±112
An overview over the output code levels is given in
– delay compensation to composite video path
– output at the luma output port
Table 2–8.
Helper signals are processed like the main video luma
signals, i.e. they are subject to scaling, sample rate
conversion and orthogonalization if activated. The
adaptive comb filter processing is switched off for the
helper lines.
2.9.8. Output Ports
All data and sync pins operate at TTL compliant levels
and can be tristated via I2C registers.
It is expected that further helper processing (e.g. non-
linear expansion, matched filter) is performed outside
the VPC.
Additionally, the data outputs can be tristated via the
YCOE output enable pin immediately. This function
allows the digital insertion of a 2nd digital video source
(e. g. MPEG aso.).
2.10.1. Output Signals for PAL+/Color+ Support
To minimize crosstalk data and clock pins automati-
cally adopt the output driver strength depending on
their specific external load (max. 50pF). Sync and Fifo
control pins have to be adjusted manually via an I2C
register.
For a PAL+/Color+ signal, the 625 line PAL image con-
tains a 16/9 core picture of 431 lines which is in stan-
dard PAL format. The upper and lower 72 lines contain
the PAL+ helper signal, and line 23 contains signalling
information for the PAL+ transmission.
For PAL+ mode, the Y signal of the core picture, which
is during lines 60–274 and 372–586, is replaced by the
orthogonal composite video input signal. In order to fit
the signal to the 8-bit port width, the ADC signal ampli-
tudes are used. During the helper window, which is in
lines 24–59, 275–310, 336–371, 587–622, the demodu-
lated helper is signal processed by the horizontal scaler
and the output circuitry. It is available at the luma output
port. The processing in the helper reference lines 23
and 623 is different for the wide screen signaling part
and the black reference and helper burst signals. The
code levels are given in detail in Table 2–8, the output
signal for the helper reference line is shown in Fig. 2–17.
2.9.9. Test Pattern Generator
The YCrCb outputs can be switched to a test mode
where YCrCb data are generated digitally in the
VPC32xx. Test patterns include luma/chroma ramps,
flat field and a pseudo color bar.
20
Micronas
MICRONAS [ MICRONAS ]
