ADV7305AKST Analog Devices Inc, ADV7305AKST Datasheet - Page 47

• Manufacturer Part Number: ADV7305AKST
• Description: IC ENCODER VIDEO 14BIT 64LQFP
• Manufacturer: Analog Devices Inc
• Type: Video Encoderr

Specifications of ADV7305AKST

• Applications: DVD, SD/HD
• Voltage - Supply, Analog: 2.5V
• Voltage - Supply, Digital: 2.5V
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Number Of Dac's: 6
• Adc/dac Resolution: 14b
• Screening Level: Commercial
• Package Type: LQFP
• Pin Count: 64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Address
00h
01h
02h
10h
11h
15h
20h
38h
39h
3Ah
3Bh
3Ch
3Dh
All other register settings are 00h.
When changing the Adaptive Filter Mode to Mode B
[Address 15h, Bit 6], the output in Figure 67 can be obtained.
The adaptive filter control can also be demonstrated using the
internally generated crosshatch test pattern and toggling the Adap-
tive Filter Control Bit [Address 15h, Bit 7], shown in Table XXII.
Address
00h
01h
02h
10h
11h
15h
20h
38h
39h
3Ah
3Bh
3Ch
3Dh
REV. A
Table XXII. Adaptive Filter Control on Internal Test Pattern
Figure 67. Output Signal from Adaptive Filter Control
Table XXI. Adaptive Filter Control on Step Input Signal
Register Setting
FCh
38h
20h
00h
81h
80h
00h
ACh
9Ah
88h
28h
3Fh
64h
Register Setting
FCh
38h
20h
00h
85h
80h
00h
ACh
9Ah
88h
28h
3Fh
64h
@: 446mV
@: 12.8ms
: 674mV
: 332ns
–47–
SD DIGITAL NOISE REDUCTION
[Subaddresses 63h, 64h, and 65h]
DNR is applied to the Y data only. A filter block selects the high
frequency, low amplitude components of the incoming signal
(DNR input select). The absolute value of the filter output is
compared to a programmable threshold value (DNR threshold
control). There are two DNR modes available: DNR Mode and
DNR Sharpness Mode.
In DNR Mode, if the absolute value of the filter output is smaller
than the threshold, it is assumed to be noise. A programmable
amount (coring gain border, coring gain data) of this noise signal
will be subtracted from the original signal.
In DNR Sharpness Mode, if the absolute value of the filter
output is less than the programmed threshold, it is assumed to
be noise, as before. Otherwise, if the level exceeds the threshold
now being identified as a valid signal, a fraction of the signal
(coring gain border, coring gain data) will be added to the origi-
nal signal in order to boost high frequency components and to
sharpen the video image.
In MPEG systems, it is common to process the video information
in blocks of 8
for MPEG1 systems (block size control). DNR can be applied to
the resulting block transition areas that are known to contain
noise. Generally, the block transition area contains two pixels. It
is possible to define this area to contain four pixels (border area).
It is also possible to compensate for variable block positioning
or differences in YCrCb pixel timing with the use of the (DNR
block offset).
Y DATA
Y DATA
INPUT
INPUT
DNR MODE
DNR
SHARPNESS
MODE
NOISE
SIGNAL PATH
NOISE
SIGNAL PATH
INPUT FILTER
INPUT FILTER
MAIN SIGNAL PATH
MAIN SIGNAL PATH
Figure 68. DNR Block Diagram
8 pixels for MPEG2 systems, or 16
BLOCK
BLOCK
< THRESHOLD ?
> THRESHOLD ?
CORING GAIN BORDER
CORING GAIN BORDER
BLOCK SIZE CONTROL
OUTPUT
OUTPUT
BLOCK SIZE CONTROL
FILTER
FILTER
CORING GAIN DATA
CORING GAIN DATA
ADV7304A/ADV7305A
BLOCK OFFSET
BLOCK OFFSET
BORDER AREA
DNR CONTROL
DNR CONTROL
BORDER AREA
FILTER OUTPUT
FILTER OUTPUT
> THRESHOLD
< THRESHOLD
GAIN
GAIN
SUBTRACT SIGNAL
IN THRESHOLD
RANGE FROM
ORIGINAL SIGNAL
ADD SIGNAL
ABOVE THRESHOLD
RANGE FROM
ORIGINAL SIGNAL
DNR OUT
DNR OUT
16 pixels