
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 12: Video Input Processor
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
12-10
value takes effect after the selected vertical reference edge occurs at the input. The
SF bit controls how the Field Identier value is interpreted. Any change of the Field
Identier interpretation takes effect immediately.
Video Acquisition Window
The start location of the window to be captured, relative to the input stream, is
specied in the Window Start registers, 00140 (
VID_XWS, VID_YWS).
The stop location of the window to be captured, relative to the input stream, is
specied in the Window End register, 00144 (
VID_XWE, VID_YWE).
Additional Target window cropping, which might be necessary after scaling, can be
done with the
LINE_SIZE and LINE_COUNT values in the Target Window Size
register, 00304.
Dithering of the Video Data
There are two identical Dither units, Pre-Dither and Post-Dither, capable of 10->9, 10-
>8 and 9->8 dithering/rounding with saturating values. These two dither units are
cascaded together on the video data path. The two dither units are independent of
each other, and controlled with separate MMIO registers. Input samples are assumed
to be left (MSB) aligned on the 10 bit input bus. Output samples are left aligned
(MSB) on the 10 bit output bus. Both Dither units need to be disabled for an 8-bit input
data stream, to avoid unexpected results.
Figure 10: Field Identier Timing
FID
VMI
HREF
VREF
FID
ZERO
start of video
window
falling edge
of VREF
start of video
window
falling edge
of VREF
FID
TGL
change of
FTGL & FZERO bits
VID
_YWS
VID
_XWS
Table 5: Field Identier Generation Modes
VDI8
HREF
VSEL
FZERO
FTGL
Change at
FID
FSWP
Meaning
x
f
VMI
0
negedge VREF
!f
0
Odd
f
x
D1
0
valid D1 Header
f
1
0
Even
x
1
0
immediately
0
1
Even
x
1
immediately*
0,1,0,..
1
Odd
* FID toggles after detection of video window start.