1.0 Functional Description
CX25870/871
1.3 Device Description
Flicker-Free Video Encoder with Ultrascale Technology
Figure 1-35. CX25870 Driving a Type II SCART Connector (Y/C and BBC SCART Compliant)
21
19
20
+3.3 V
18
16
3.3 V
17
CX25870/871
Y/R
15
13
Std Def
LPF
14
12
10
3.3 V
11
9
Std Def
LPF
C/G
8
6
7
CVBS/B
5
4
2
3
1
75 Ω
1%
75 Ω
1%
SCART
Connector
100381_093
Conexant recommends that any designer utilizing the CX25870 with either
type of SCART output utilize the same DAC low-pass filters used for standard
definition TV outputs listed in Chapter 3.0 of this data sheet.
1.3.44 Interlaced Standard Definition Analog Component Video TV Outputs
In this mode of operation, the CX25870/25871 provides a set of Component
Video Y, PB (B–Y), PR (R–Y) outputs based on a 480 line interlaced RGB or
YCrCb digital input format. Some DVD Players, such as those made by Toshiba
and Panasonic, call the Component Video Output format by their branded name,
“ColorStream.” Others refer to the two EIA standards governing this video
format–EIA-770.1 and EIA-770.2-A, and state this video type as Interlaced
Component Video, 480i Component Video, or Component YUV. Regardless of
the different names, the video format remains the same. For instructions on how
to configure the CX25870/871 to generate progressive 480p Component Video
(or ColorStream Pro), refer to that particular section in this data sheet.
The designer can enable ColorStream by using three of the CX25870’s DACs
to generate two color difference signals (PR and PB sometimes referred to as CR
and CB) and a single luminance signal (Y). These three channels allow the video
generating device to bypass the TV’s internal Y/C separator and color decoder
circuits. The analog information therefore gets routed directly into the TV’s
matrix decoder. By sending the pure component video signal directly to a
Component Video or ColorStream input-equipped display media, the input signal
forgoes the extra processing that normally would degrade the analog image.
1-80
Conexant
100381B
CONEXANT [ CONEXANT SYSTEMS, INC ]
