AK8859VN Datasheet, PDF (30/72 Pages) Asahi Kasei Microsystems – NTSC/PAL/SECAM Digital Video Decoder

[AK8859VN]
[7.22.] Output Interface
[7.22.1.] 656 interface
[7.22.1.1.] Line-locked and frame-locked clock modes
The AK8859VN data output in both of these modes are compliant with ITU-R BT.656, which is requires the
following samples and line numbers.
- Number of samples for 1 line:
858 samples (525i) / 864 samples (625i)
- Number of lines for 1 frame: 525 lines / 625 lines
It may not be possible, however to meet these requirement if the input signal quality is poor.
In the event of output-stage buffer failure, line drop/repeat processing will be performed.
A line drop or a line repeat will result in output signal with 524/624 or 526/626 lines per frame respectively.
Line drop/repeat processing may be performed at any line in the frame.
[7.22.1.2.] Fixed-clock mode
In fixed-clock mode, operation is at an internally generated 27 MHz clock, from a 24.576 MHz input clock.
The output signal is therefore not synchronized with the input signal, and thus not ITU-R BT.656 compliant.
Data is output in SAV format. As shown in the following figure, EAV is guaranteed for 720 pixels from SAV,
but the number of pixels from EAV to SAV is not.
SAV
720 pixels
EAV
858 / 864 ( NTSC / PAL ) pixels ± α
When the fixed-clock mode is performed, the active area of the output data is determined by SAV standard.
MS1179-E-00
AKM Confidential
- 30 -
2010/04