AK8858 Datasheet, PDF (29/96 Pages) Asahi Kasei Microsystems – PS/SD Multi Format Video Decoder

[7.6] Auto detection mode of input signal
The video input signal can be automatically detected (auto detection mode) via register.
[AK8858]
Settings for auto detection of input signal (auto detetction mode)
Name
Setting
ON/OFF
AUTODET
0
1
OFF(Manual setting)
ON
Sub Address: 0x04 [7]
Notes
The auto detetction recognizes the following parameters (AUTODET-bit=1).
Number of lines per frame:
Subcarrier frequency:
Color encoding formats:
Progressive setting:
Monochrome signal*:
525/626
3.57954545 (MHz)
3.57561149 (MHz)
3.58205625 (MHz)
4.43361875 (MHz)
NTSC/PAL/SECAM
Interlace / Progressive
Not monochrome/monochrome.
*Note: Automatic monochrome detection is active if the color kill setting is ON.
The detected result of auto detetction mode is reflected to Input Video Status Register. The input signal status
can be recognized by reading this register.
bit 7
bit 6
bit 5
bit 4
bit 3
FIXED UNDEF ST_BW ST_VLF ST_VCEN1
bit 2
ST_VCEN0
Sub Address: 0x25
bit 1
bit 0
ST_VSCF1 ST_VCSF0
In addition, auto detetction function of the input signal is recognized by the changing of internal status.
If FIXED-bit changed from 0 to 1, the detetction is completed. During FIXED-bit is 0, the AK8858 may attempt
to recognize the input signal and the output code during this period cannot be trusted. If the AK8858 cannot
recognize the input signal, UNDEF-bit is changed from 0 to 1 to indicate the status of the input signal.
MS1230-E-00
- 29 -
2010/9