Analog Devices ADV8005 Hardware Reference Manual page 251

ADV8005 Hardware Reference Manual
1 Pass-band ripple is the maximum fluctuation from the 0 dB response in the pass band, measured in decibels. The pass band is defined to have 0 Hz to fc (Hz) frequency
limits for a low-pass filter and 0 Hz to f1 (Hz), and f2 (Hz) to infinity for a notch filter, where fc, f1, and f2 are the −3 dB points.
2
3 dB bandwidth refers to the −3 dB cutoff frequency.
The luma filter supports several different frequency responses, including two low-pass responses, two notch responses, an extended (SSAF)
response with or without gain boost attenuation, a CIF response, and a QCIF response. These can be configured using luma_filter_sel[2:0].
luma_filter_sel[2:0], Encoder Map, Address 0xE480[4:2]
This signal is used to configure the luma filters for SD data.
Function
luma_filter_sel[2:0]
000
001
010
011
100 (default)
101
110
111
If SD SSAF gain is enabled, there are 13 response options in the −4 dB to +4 dB range. The desired response can be programmed using register
0xA2. The variation in frequency responses is shown in
controlling the SSAF filter gain are described below.
Filter Pass-Band Ripple (dB)
Chroma 1.3 MHz 0.09
Chroma 2.0 MHz 0.048
Chroma 3.0 MHz Monotonic
Chroma CIF Monotonic
Chroma QCIF Monotonic
Description
LPF NTSC
LPF PAL
Notch NTSC
Notch PAL
SSAF Luma
Luma CIF
Luma QCIF
Reserved
4
2
0
–2
–4
–6
–8
–10
–12
0 1
Figure 112: SD Luma SSAF Filter, Programmable Responses
3 dB Bandwidth (MHz)
1
1.395
2.2
3.2
0.65
0.5
Figure 112, Figure 113, and
2 3 4 5
FREQUENCY (MHz)
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2
Figure 114. The registers required for enabling and
6 7
UG-707