ADV8005 Hardware Reference Manual
UG-707
7.4.3.
SD VCR FF/RW Synchronization
In DVD record applications where the encoder is used with a decoder, the VCR FF/RW synchronization control bit can be used for nonstandard
input video. This is in fast forward or rewind modes.
In fast forward mode, the sync information at the start of a new field in the incoming video usually occurs before the correct number of
lines/fields is reached. In rewind mode, this sync signal usually occurs after the total number of lines/fields is reached. Conventionally, this
means that the output video has corrupted field signals because one signal is generated by the incoming video and another is generated when
the internal line/field counters reach the end of a field.
When the VCR FF/RW sync control is enabled (
= 1), the line/field counters are updated according to the incoming VSync signal and
when the analog output matches the incoming VSync signal. This control is available in all slave timing modes except slave mode 0.
dvd_r
, Encoder Map,
Address 0xE482[5]
This bit is used to enable the SD VCR FF/RW sync feature.
Function
dvd_r
Description
1
Enabled
0 (default)
Disabled
7.4.4.
Vertical Blanking Interval
The
encoder core is able to accept input data that contains VBI data (such as CGMS, WSS, VITS) in SD, ED, and HD modes.
If VBI is disabled, VBI data is not present at the output and the entire VBI is blanked. These control bits are valid in all master and slave timing
modes. In order to enable this feature,
is set to 1.
For the SMPTE 293M (525p) standard, VBI data can be inserted on Line 13 to Line 42 of each frame or on Line 6 to Line 43 for the ITU-R
BT.1358 (625p) standard. VBI data can be present on Line 10 to Line 20 for NTSC and on Line 7 to Line 22 for PAL. If CGMS is enabled and
VBI is disabled, the CGMS data is, nevertheless, available at the output.
7.4.5.
SD Subcarrier Frequency Control
The
encoder core is able to generate the color subcarrier used in CVBS and S-Video (Y-C) outputs from the input pixel clock. Four 8-
bit registers are used to set up the subcarrier frequency. The value of these registers is calculated using
32
2
MHz
27
×
=
line
video
one
in
cycles
clk
of
Number
line
video
one
in
periods
subcarrier
of
Number
Register
Frequency
Subcarrier
Equation 27: SD Subcarrier Frequency Calculation
where the sum is rounded to the nearest integer. For example, in NTSC mode:
569408543
2
1716
5
.
227
32
=
×
=
Value
Register
Subcarrier
Equation 28: SD Subcarrier Frequency Calculation
where:
Subcarrier Register Value = 569408543d = 0×21F07C1F
SD F
SC
Register 0: 0x1F
SD F
SC
Register 1: 0x7C
SD F
SC
Register 2: 0xF0
SD F
SC
Register 3: 0x21
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