Akai PDP4294LV1, Service Manual

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Complete Stand-Alone Line 21 Decoder for Closed-
Captioned and Extended Data Services (XDS)
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Preprogrammed to Provide Full Compliance with
EIA–608 Specifications for Extended Data Services
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Automatic Extraction and Serial Output of Special
XDS Packets (Time of Day, Local Time Zone, and
Program Blocking)
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Programmable XDS Filter for a Specific XDS Packet
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Cost-Effective Solution for NTSC Violence Blocking
inside Picture-in-Picture (PiP) Windows
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Minimal Communications and Control Overhead Pro-
vide Simple Implementation of Violence Blocking,
Closed Captioning, and Auto Clock Set Features
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Programmable, On-Screen Display (OSD) for Creat-
ing Full Screen OSD or Captions inside a Picture-in-
Picture (PiP) Window
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User-Programmable Horizontal Display Position for
easy OSD Centering and Adjustment
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I
2
C Serial Data and Control Communication
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Supports 2 Selectable I
2
C Addresses
Capable of processing Vertical Blanking Interval (VBI)
data from both fields of the video frame in data, the Z86229
Line 21 Decoder offers a feature-rich solution for any tele-
vision or set-top application. The robust nature of the
Z86229 helps the device conform to the transmission format
defined in the Television Decoder Circuits Act of 1990, and
in accordance with the Electronics Industry Association
specification 608 (EIA–608).
The Line 21 data stream can consist of data from several data
channels multiplexed together. Field 1 consists of four data
channels: two Captions and two Texts. Field 2 consists of
five additional data channels: two Captions, two Texts, and
Extended Data Services (XDS). The XDS data structure is
defined in EIA–608. The Z86229 can recover and display
data transmitted on any of these nine data channels.
The Z86229 can recover and output to a host processor via
the I
2
C serial bus. The recovered XDS data packet is further
defined in the EIA–608 specification. The on-chip XDS fil-
ters in the Z86229 are fully programmable, enabling recov-
ery of only those XDS data packets selected by the user. This
functionality allows the device to extract the required XDS
information with proper XDS filter setup for compatibility
in a variety of TVs, VCRs, and Set-Top boxes.
In addition, the Z86229 is ideally suited to monitor Line 21
video displayed in a PiP window for violence blocking,
CCD, and other XDS data services. A block diagram of the
Z86229 is illustrated in Figure 1.
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