Philips Semiconductors
Digital video scaler
Preliminary specification
SAA7186
shorter than XS, processing is aborted when the falling
edge of HREF is detected.
Vertical regions in Fig.4:
• the two regions can be programmed via I2C-bus,
whereby regions should not overlap (active region
overrides the bypass region).
• the start of a normal active picture depends on video
standard and has to be programmed to the correct
value.
• the offsets XO and YO have to be set according to the
internal processing delays to ensure the complete
number of destination pixels and lines (Table 6).
• the scaling parameters can be used to perform a
panning function over the video frame/field.
handbook, full pagewidth
LLC
CREF
HREF
Byte numbers for pixles:
Y signal
U and V signal
start of
active line
0
1
2
3
4
5
6
7
U0
V0
U2
V2
U4
V4
U6
V6
MEH411
handbook, full pagewidth
LLC
CREF
HREF
Byte number for pixels:
Y signal
n–5
U and V signal
Un-5
n–4
Vn-5
n–3
Un-3
n–2
Vn-3
end of
active line
n–1
n
Un-1
Vn-1
May 1993
Fig.3 Horizontal and data multiplex timing.
11
MEH410