VSP 94x2A
DATA SHEET
2.5.3. Coarse and Fine Delay
PKLY
Before digital-to-analog conversion an adjustment of
the phase of the luminance is performed. A coarse
delay from −8 to +7 in steps of 1 pixel CLKB36
(~28 ns) is possible (COARSEDEL). FINEDEL shifts
the luminance one CLKB72 (~14 ns) pixel. This can be
used to compensate delays, if the external processing
of Y and UV produces different delays (e.g. external
lowpass filtering).
128 LSB upper headroom for peaking
240 LSB normal
signal range
'black'
16 LSB
2.5.4. Oversampling and DAC
128 LSB lower headroom for peaking
After conversion into 8:8:8 format (CLKB72=72 MHz),
three 9-bit digital-to-analog converters are used for
analog YUV output. This twofold-oversampling gener-
ates 1920 active pixels per line (when using recom-
mended settings) and simplifies the external postfilter-
ing. The output voltage is determined by PKLY, PKLU
and PKLV and can be set in a range of 0.4 V ...1.9 V
(fullscale).
0 V
PKLU
PLLV
CHROMAMP=1
CHROMAMP=0
'no color'
8 bits of the luminance D/A converter are used for the
entire signal. The 9th bit is used for over- and under-
shoots caused by the peaking to prevent or reduce
clipping artifacts. As the CTI block seldomly produces
such overshoots, a full-scale operation can be acti-
vated by CHROMAMP. The output voltages may be
calculated by:
Fig. 2–36: DAC Output Signals
PKLY
256
+ 0.36V ⋅ signalY
---------------
VoltageY = 1.56V ⋅
2.5.5. Output-Sync Controller
The output sync controller generates horizontal and
vertical synchronization signals for the scanrate-con-
verted output signal.
160....400
-----------------------
signalY =
512
The number of pixels per line is 4*PPLOP. The default
value of 288 results in 1152 pixels/line. With
CLKB= 36 MHz, the horizontal output frequency is
31.25 kHz, which is twice the PAL horizontal fre-
quency. Out of these pixels, 16*APPLOP are displayed
as active picture area, which are 960 by default. The
position on the screen depends on the NAPPLOP. It
marks the picture area not active in horizontal direction
and moves the active picture in horizontal direction.
The number of lines per field is 2*LPFOP. This value is
only used in the vertical freeruning mode. In vertical
locked mode, the number of lines per field is derived
from the CVBS signal itself and not adjustable. The
active and non-active picture areas are marked by
ALPFOP and NALPFOP, respectively.
[for unpeaked signals max.]
0....511
signalY = -----------------
512
[for peaked signals max.]
PKLU, V
256
----------------------
VoltageU, V = 1.56V ⋅
+ 0.36V ⋅ CHROMAMP ⋅ signalUV
Both generators have a so called ‘locked-mode’ and
‘freeruning-mode’. Not all combinations of these
modes make sense. Table 2–13 on page 27 shows
ingenious configurations.
128....384
512
signalUV = -----------------------
26
Aug. 16, 2004; 6251-552-1DS
Micronas
MICRONAS [ MICRONAS ]
