AK8853XQ Datasheet, PDF (31/70 Pages) Asahi Kasei Microsystems – NTSC/PAL/SECAM Digital Video Decoder

[AK8853XQ/ VN]
7.17 Automatic setup processing
In auto detection mode, the AK8853 can perform automatic setup processing in accordance with the
detected signal. The automatic setup selection is made via the STUPATOFF-bit register, as shown in the
table below.
Setup processing of the signal to be decoded consists of the following.
Luminance signal: Y=(Y-7.5)/0.925
Color signal:
U=U/0.925, V=V/0.925
Automatic setup processing (AK8853 in auto detection mode)
Register setting
Detected signal
Setup-bit
STUPATOFF-bit
(Automatic setup processing)
[0]
[0]
NTSC-M, J
PAL-B, D, G, H, I, N
[1]
PAL-Nc, 60
SECAM
[0]
[1]
[1]
Detected signal setup
processing status
Disabled
Disabled
Enabled
Enabled
[0]
[0]
PAL-M
[1]
NTSC-4.43
[0]
[1]
[1]
Enabled
Disabled
Enabled
Enabled
In the auto detection mode, the setup processing status will be determined by the register setting on the
basis of the detected signal category, with no detection as to the presence or absence of input signal
setup.
7.18 PGA (programmable gain amp)
The PGA, located in the input stage of the AK8853, can be set in a gain range of -6~6 dB in gain steps
of 0.1 dB.
PGA[7:0]-bits: Sets the PGA value.
This register can read the AGC setting value.
If AGC is enabled, the PGA[7:0]-bits setting value has no effect, and the PGA setting can be
manually entered in the register only if AGC is disabled.
Signal input to the AK8853 should be made with the input level attenuated approximately 39%
(-8.19 dB) by resistance splitting.
Rev-E-00
31
2008/01