GS1503B Gennum Corporation, GS1503B Datasheet - Page 36

• Manufacturer Part Number: GS1503B
• Description: Hd Embedded Audio Codec
• Manufacturer: Gennum Corporation

4.8 Video Switching Line Setting
Table 4-27: Register Settings
Name
SW_LNA[12:0]
SW_LNB[12:0]
Description
Video Field 1 switching point setting
Video Field 2 switching point setting
The video switching point for field 1 and field 2 can be configured via the GS1503B
Host Interface. The SW_LNA[12:0] register is used to configure the video switching
line for field 1, and SW_LNB[12:0] to set video switching line for field 2. In
progressive format video standards, only the SW_LNA[12:0] register is used. The
default settings are line 7 for field 1 and line 569 for field 2 as defined in SMPTE
299M.
The GS1503B will not multiplex any audio data packets in the line immediately after
the video switching point. For example, with the default setting of line 7 field 1,
there will be no audio data packets in line 8. The next packets will appear on line
9. Audio control packets will be multiplexed once per field, two lines after the video
switching point (on line 9, using the previous example). Arbitrary data packets will
not be multiplexed in the two lines following the video switching point .
NOTE: The SMPTE 299M standard defines the video switching point as lines 7 and
569. If the SW_LNA[12:0] and SW_LNB[12:0] registers are programmed with
values other than lines 7 and 569, the output of the GS1503B is not guaranteed to
be compatible with all HD audio demultiplex systems. With non-SMPTE 299M
compliant switch line settings, the user should avoid inputting a video data stream
to the GS1503B, which already contains embedded audio data and control
packets.
For reliable operation, non-SMPTE 299M compliant video data streams with
embedded audio should not be used in conjunction with the GS1503B in Multiplex
Mode.
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Bit
4-0
7-0
4-0
7-0
GS1503B Data Sheet
Setting
–
–
Default
569d
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7d