ADVANCE INFORMATION
VDP 313xY
2.12.2.Angle & Bow Correction
Note: The processing delay of the internal digital video
path differs depending on the comb filter option of the
VDP 313xY. The versions with comb filter have an
additional delay of 34 clock cycles.
The Angle & Bow correction is part of the horizontal
drive PLL. This feature allows a shift of the horizontal
drive pulse phase depending on the vertical position
on the screen. The phase correction has a linear
(angle) and a quadratic term (bow).
2.12.4.Vertical and East/West Deflection
The calculations of the vertical and East/West deflec-
tion waveforms is done by the internal Fast Processor
(FP). The algorithm uses a chain of accumulators to
generate the required polynomial waveforms. To pro-
duce the deflection waveforms, the accumulators are
initialized at the beginning of each field. The initializa-
tion values must be computed by the TV control pro-
cessor and are written to the front-end once. The
waveforms are described as polynomials in x, where x
varies from 0 to 1 for one field.
2.12.3.Horizontal Phase Adjustment
This section describes a simple way to align PLL
phases and the horizontal frame position.
1. With HDRV the duration of the horizontal drive pulse
has to be adjusted
2. With POFS2 the delay between input video and dis-
play timing (e.g. clamping pulse for analog RGB)
has to be adjusted
P: a + b(x−0.5) + c(x−0.5)2 + d(x−0.5)3 + e(x−0.5)4
3. With CSYDEL the delay between video and analog
RGB (OSD) has to be adjusted.
The initialization values for the accumulators a0..a3 for
vertical deflection and a0..a4 for East/West deflection
are 12-bit values.
4. With CSYDEL and HPOS the horizontal position of
both, the digital and analog RGB signal (from
SCART) relative to the clamping pulse has to be
adjusted to the correct position, e.g. the pedestal of
the generator signal.
Fig. 2–25 shows several vertical and East/West deflec-
tion waveforms. The polynomial coefficients are also
stated.
5. With POFS3 the position of horizontal drive/flyback
relative to RGB has to be adjusted
In order to get a faster vertical retrace timing, the out-
put impedance of the vertical D/A-converter is reduced
during the retrace.
6. With NEWLIN the position of a scaled video picture
can be adjusted (left, middle, center, etc; versions
with panorama scaler only).
7. With HBST and HBSO, the start and stop values for
the horizontal blanking have to be adjusted.
Vertical:
a,b,c,d
0,1,0,0
0,1,1,0
0,1,0,1
East/West:
a,b,c,d,e
0,0,1,0,0
0,0,0,0,1
0,0,1,1,1
Fig. 2–25: Vertical and East/West Deflection Waveforms
Micronas
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MICRONAS [ MICRONAS ]
