ADVANCE INFORMATION
VPC 323xD, VPC 324xD
analog fast
blank input
Table 2–2: CIP softmixer modes
2
reading I C
I2C
SELLIN
RGB
DLY
FBCLP
FB
MODE
register <27>
1
0
0
1
0
0
1
1
0
0
0
0
0
0
0
0
1
1
<27>FBLSTAT
<27>FBLRISE
<27>FBLFALL
<27>FBLHIGH
CIP
mode
0
1
Force
YCrCb
main
0
0
0
0
x
11
Fig. 2–11: Fast Blank Monitor
Force
RGB/
YCrCb
x
x0
An additional monitoring bit is also provided for the
RGB/YCrCb signal; it indicates whether the ADCs
inputs are clipped or not. In case of clipping conditions
(1Vpp RGB input for example) the ADC range can be
extended by 3db by using the XAR bit.
Static
Mixer
0
0
1
0
0
1
1
0
0
01
01
01
– CLIPD: set by RGB/YCrCb input clip, reset by regis-
ter read
FB
Linear
FB non-
Linear
2.5. Horizontal Scaler
The 4:2:2 YCrCb signal from the mixer output is pro-
cessed by the horizontal scaler. It contains a lowpass-
filter, a prescaler, a scaling engine and a peaking filter.
The scaler block allows a linear or nonlinear horizontal
scaling of the input signal in the range of 1/32 to 4.
Nonlinear scaling, also called “panorama vision”, pro-
vides a geometrical distortion of the input picture. It is
used to fit a picture with 4:3 format on a 16:9 screen by
stretching the picture geometry at the borders. Also,
the inverse effect - called water glass - can be pro-
duced by the scaler. A summary of scaler modes is
given in Table 2–3.
2.4.5. 4:4:4 to 4:2:2 Downsampling
After the mixer, the 4:4:4 YCrCb_mix data stream is
downsampled to the 4:2:2 format. For this sake, a
chroma lowpass filter is provided to eliminate high-fre-
quency components above 5-6 Mhz which may typi-
cally be present on inserted high resolution RGB/
YCrCb sources.
In case of main video processing (loopthrough) only, it
is recommended to bypass this filter by using the I2C
bit CIPCFBY.
2.5.1. Horizontal Lowpass-filter
The luma filter block applies anti-aliasing lowpass fil-
ters. The cutoff frequencies are selectable and have to
be adapted to the horizontal scaling ratio.
2.4.6. Fast Blank and Signal Monitoring
The analogue Fast Blank state is monitored by means
of four I2C readable bits. These bits may be used by
the TV controller for SCART signal ident:
– FBHIGH: set by FB high, reset by register read at
FB low
– FBSTAT: FB status at register read
– FBRISE: set by FB rising edge, reset by register
read
– FBFALL: set by FB falling edge, reset by register
read
Micronas
15
MICRONAS [ MICRONAS ]
