Multiformat video decoder supports NTSC-(J, M, 4.43),
PAL-(B/D/G/H/I/M/N), SECAM
Integrates three 54 MHz, 9-bit ADCs
Clocked from a single 27 MHz crystal
Line-locked clock-compatible (LLC)
Adaptive Digital Line Length Tracking (ADLLT™)
5-line adaptive comb filters
Proprietary architecture for locking to weak, noisy, and
unstable video sources such as VCRs and tuners
Subcarrier frequency lock and status information output
Integrated AGC with adaptive peak white mode
Macrovision® copy protection detection
YPrPb component (VESA, MII, SMPTE, and Betacam)
6 analog video input channels
Automatic NTSC/PAL/SECAM identification
Digital output formats (8-bit or16-bit):
ITU-R BT.656 YCrCb 4:2:2 output + HS, VS, and FIELD
0.5 V to 1.6 V analog signal input range
Differential gain: 0.6% typ
GENERAL DESCRIPTION
The ADV7181 integrated video decoder automatically detects
and converts a standard analog baseband television signal
compatible with worldwide standards NTSC, PAL, and SECAM
into 4:2:2 component video data compatible with 16-/8-bit
CCIR601/CCIR656.
The advanced, highly flexible digital output interface enables
performance video decoding and conversion in line-locked
clock-based systems. This makes the device ideally suited for a
broad range of applications with diverse analog video characteristics, including tape-based sources, broadcast sources,
security/surveillance cameras, and professional systems.
The six analog input channels accept standard composite,
S-Video, YPrPb video signals in an extensive number of
combinations. AGC and clamp restore circuitry allow an input
video signal peak-to-peak range of 0.5 V up to 1.6 V.
Alternatively, these can be bypassed for manual settings.
ADV7181
Differential phase: 0.6° typ
Programmable video controls:
Peak-white/hue/brightness/saturation/contrast
Integrated on-chip video timing generator
Free run mode (generates stable video ouput with no I/P)
VBI decode support for
Close captioning, WSS, CGMS, EDTV, Gemstar® 1×/2×
Power-down mode
2-wire serial MPU interface (I
3.3 V analog, 1.8 V digital core; 3.3 V IO supply
Temperature grade: –40°C to +85°C
64-lead LQFP Pb-free package
APPLICATIONS
DVD recorders
PC video
HDD-based PVRs/DVDRs
LCD TVs
Set-top boxes
Security systems
Digital televisions
Portable video devices
Automotive entertainment
AVR receiver
The fixed 54 MHz clocking of the ADCs and datapath for all
modes allow very precise, accurate sampling and digital
filtering. The line-locked clock output allows the output data
rate, timing signals, and output clock signals to be synchronous,
asynchronous, or line locked even with ±5% line length
variation. The output control signals allow glueless interface
connections in almost any application. The ADV7181 modes
are set up over a 2-wire, serial, bidirectional port (I
compatible).
The ADV7181 is fabricated in a 3.3 V CMOS process. Its
monolithic CMOS construction ensures greater functionality
with lower power dissipation.
The ADV7181 is packaged in a small 64-lead LFCSP and LQFP
and Pb-free packages.
2
C®-compatible)
2
C-
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
Changes to Global Pin Control Section.......................................16
Changes to Table 202 ......................................................................91
Changes to Table 203 ......................................................................92
Added package in Outline Dimensions Section .......................103
Changes to Ordering Guide.........................................................104
5/04—Revision 0: Initial Version
Rev. B | Page 3 of 104
ADV7181
INTRODUCTION
The ADV7181 is a high quality, single chip, multiformat video
decoder that automatically detects and converts PAL, NTSC,
and SECAM standards in the form of composite, S-Video, and
component video into a digital ITU-R BT.656 format.
The advanced, highly flexible digital output interface enables
performance video decoding and conversion in line-locked
clock-based systems. This makes the device ideally suited for a
broad range of applications with diverse analog video characteristics, including tape-based sources, broadcast sources,
security/surveillance cameras, and professional systems.
ANALOG FRONT END
The ADV7181 analog front end comprises three 9-bit ADCs
that digitize the analog video signal before applying it to the
standard definition processor. The analog front end employs
differential channels to each ADC to ensure high performance
in mixed-signal applications.
The front end also includes a 6-channel input mux that enables
multiple video signals to be applied to the ADV7181. Current
and voltage clamps are positioned in front of each ADC to
ensure that the video signal remains within the range of the
converter. Fine clamping of the video signals is performed
downstream by digital fine clamping within the ADV7181. The
ADCs are configured to run in 4× oversampling mode.
STANDARD DEFINITION PROCESSOR
The ADV7181 is capable of decoding a large selection of
baseband video signals in composite, S-Video, and component
formats. The video standards supported by the ADV7181
include PA L B /D/I/G / H, PAL60 , PA L M, PAL N , PAL Nc ,
NTSC M/J, NTSC 4.43, and SECAM B/D/G/K/L. The
ADV7181 can automatically detect the video standard and
process it accordingly.
The ADV7181 has a 5-line, superadaptive, 2D comb filter that
gives superior chrominance and luminance separation when
decoding a composite video signal. This highly adaptive filter
automatically adjusts its processing mode according to video
standard and signal quality with no user intervention required.
Video user controls such as brightness, contrast, saturation, and
hue are also available within the ADV7181.
The ADV7181 implements a patented adaptive digital linelength tracking (ADLLT) algorithm to track varying video line
lengths from sources such as a VCR. ADLLT enables the
ADV7181 to track and decode poor quality video sources such
as VCRs, noisy sources from tuner outputs, VCD players, and
camcorders. The ADV7181 contains a chroma transient
improvement (CTI) processor that sharpens the edge rate of
chroma transitions, resulting in sharper vertical transitions.
The ADV7181 can process a variety of VBI data services such as
closed captioning (CC), wide screen signaling (WSS), copy generation management system (CGMS), EDTV, Gemstar 1×/2×,
and extended data service (XDS). The ADV7181 is fully
Macrovision certified; detection circuitry enables Type I, II, and
III protection levels to be identified and reported to the user.
The decoder is also fully robust to all Macrovision signal inputs.
Rev. B | Page 4 of 104
ADV7181
FUNCTIONAL BLOCK DIAGRAM
04820-001
HS
VS
PIXEL
DATA
8
8
16
FIELD
LLC
SFL
OUTPUT FORMATTER
LUMA
(4H MAX)
2D COMB
LUMA
RESAMPLE
GAIN
CONTROL
LUMA
FILTER
STANDARD DEFINITION PROCESSOR
FINE
LUMA
CLAMP
DIGITAL
9
9
L-DNR
AV
LINE
CODE
INSERTION
CONTROL
RESAMPLE
LENGTH
PREDICTOR
SYNC
EXTRACT
CTI
SC
F
C-DNR
RECOVERY
(4H MAX)
CHROMA
2D COMB
CHROMA
RESAMPLE
GAIN
CONTROL
FILTER
CHROMA
DEMOD
CHROMA
FINE
CLAMP
DIGITAL
CHROMA
FREE RUN
SYNTHESIZED
LLC CONTROL
OUTPUT CONTROL
STANDARD
AUTODETECTION
DETECTION
MACROVISION
VBI DATA RECOVERYGLOBAL CONTROL
DATA
9
6
PREPROCESSOR
A/DCLAMP
AIN1–AIN6
FILTERS
DOWNSAMPLING
DECIMATION AND
9
A/DCLAMP9A/DCLAMP
MUX
INPUT
CVBS
YPrPb
S-VIDEO
SYNC AND
CLK CONTROL
CLOCK GENERATION
SYNC PROCESSING AND
Figure 1.
Rev. B | Page 5 of 104
ADV7181
CONTROL
AND DATA
SERIAL INTERFACE
CONTROL AND VBI DATA
SDA
SCLK
ALSB
ADV7181
SPECIFICATIONS
Temperature range: T
ELECTRICAL CHARACTERISTICS
A
= 3.15 V to 3.45 V, D
VDD
otherwise noted.
Table 1.
Parameter Symbol Test Conditions Min Typ Max Unit
STATIC PERFORMANCE
Resolution (Each ADC) N 9 Bits
Integral Nonlinearity INL BSL at 54 MHz –0.475/+0.6 –1.5/+2 LSB
Differential Nonlinearity DNL BSL at 54 MHz –0.25/+0.5 –0.7/+2 LSB
DIGITAL INPUTS
Input High Voltage VIH 2 V
Input Low Voltage VIL 0.8 V
Input Current IIN Pin 29 –50 +50 µA
All other pins –10 +10 µA
Input Capacitance CIN 10 pF
DIGITAL OUTPUTS
Output High Voltage VOH I
Output Low Voltage VOL I
High Impedance Leakage Current I
Output Capacitance C
POWER REQUIREMENTS1
Digital Core Power Supply D
Digital I/O Power Supply D
PLL Power Supply P
Analog Power Supply A
Digital Core Supply Current I
Digital I/O Supply Current I
PLL Supply Current I
Analog Supply Current I
YPrPb input3 180 mA
Power-Down Current I
Power-Up Time t
1
Guaranteed by characterization.
2
ADC1 and ADC2 powered down.
3
All three ADCs powered on.
to T
MIN
MAX
= 1.65 V to 2.0 V, D
VDD
, –40°C to +85°C. The min/max specifications are guaranteed over this range.
= 3.0 V to 3.6 V, P
VDDIO
SOURCE
= 3.2 mA 0.4 V
SINK
10 µA
LEAK
20 pF
OUT
1.65 1.8 2 V
VDD
3.0 3.3 3.6 V
VDDIO
1.65 1.8 2.0 V
VDD
3.15 3.3 3.45 V
VDD
80 mA
DVDD
2 mA
DVDDIO
10.5 mA
PVDD
CVBS input2 85 mA
AVDD
1.5 mA
PWRDN
20 ms
PWRUP
= 1.65 V to 2.0 V; operating temperature range, unless
VDD
= 0.4 mA 2.4 V
Rev. B | Page 6 of 104
ADV7181
VIDEO SPECIFICATIONS
Guaranteed by characterization. A
temperature range, unless otherwise noted.
SNR Unweighted Luma ramp 54 dB
Luma flat field 58 dB
Analog Front End Crosstalk 60 dB
LOCK TIME SPECIFICATIONS
Horizontal Lock Range –5 +5 %
Vertical Lock Range 40 70 Hz
Fsc Subcarrier Lock Range ±1.3 kHz
Color Lock In Time 60 Lines
Sync Depth Range 20 200 %
Color Burst Range 5 200 %
Vertical Lock Time 2 Fields
Autodetection Switch Speed 100 lines
Luma Brightness Accuracy CVBS, 1 V I/P 1 %
Luma Contrast Accuracy CVBS, 1 V I/P 1 %
= 3.15 V to 3.45 V, D
VDD
= 1.65 V to 2.0 V, D
VDD
= 3.0 V to 3.6 V, P
VDDIO
= 1.65 V to 2.0 V; operating
VDD
Rev. B | Page 7 of 104
ADV7181
TIMING SPECIFICATIONS
Guaranteed by characterization. A
temperature range, unless otherwise noted.
Table 3.
Parameter Symbol Test Conditions Min Typ Max Unit
SYSTEM CLOCK AND CRYSTAL
Nominal Frequency 27.00 MHz
Frequency Stability ±50 ppm
I2C PORT
SCLK Frequency 400 kHz
SCLK Min Pulse Width High t1 0.6 µs
SCLK Min Pulse Width Low t2 1.3 µs
Hold Time (Start Condition) t3 0.6 µs
Setup Time (Start Condition) t4 0.6 µs
SDA Setup Time t5 100 ns
SCLK and SDA Rise Time t6 300 ns
SCLK and SDA Fall Time t7 300 ns
Setup Time for Stop Condition t8 0.6 µs
RESET FEATURE
Reset Pulse Width 5 ms
CLOCK OUTPUTS
LLC1 Mark Space Ratio t9:t10 45:55 55:45 % Duty Cycle
DATA AND CONTROL OUTPUTS
Data Output Transitional Time t11
Data Output Transitional Time t12
= 3.15 V to 3.45 V, D
VDD
= 1.65 V to 2.0 V, D
VDD
= 3.0 V to 3.6 V, P
VDDIO
Negative clock edge to start of valid data.
= t
(t
ACCESS
10
– t11)
End of valid data to negative clock edge.
(t
= t9 + t12)
HOLD
= 1.65 V to 2.0 V; operating
VDD
6 ns
0.6 ns
ANALOG SPECIFICATIONS
Guaranteed by characterization. At A
operating temperature range, unless otherwise noted. Recommended analog input video signal range: 0.5 V – 1.6 V, typically 1 V p-p.
Table 4.
Parameter Symbol Test Conditions Min Typ Max Unit
CLAMP CIRCUITRY
External Clamp Capacitor 0.1 µF
Input Impedance Clamps switched off 10 MΩ
Large Clamp Source Current 0.75 mA
Large Clamp Sink Current 0.75 mA
Fine Clamp Source Current 60 µA
Fine Clamp Sink Current 60 µA
= 3.15 V to 3.45 V, D
VDD
= 1.65 V to 2.0 V, D
VDD
= 3.0 V to 3.6 V, P
VDDIO
= 1.65 V to 2.0 V;
VDD
THERMAL SPECIFICATIONS
Table 5.
Parameter Symbol Test Conditions Min Typ Max Unit
THERMAL CHARACTERISTICS
4-layer PCB with solid ground plane, 64-lead LFCSP 45.5 °C/W
4-layer PCB with solid ground plane, 64-lead LFCSP 9.2 °C/W
4-layer PCB with solid ground plane, 64-lead LQFP 47 °C/W
Rev. B | Page 8 of 104
ADV7181
TIMING DIAGRAMS
t
t
t
7
5
1
Figure 2. I
2
C Timing
SDA
SCLK
t
3
t
6
t
2
t
3
t
4
t
8
04820-002
OUTPUT LLC1
OUTPUTS P0–P15, VS,
HS, FIELD, SFL
t
9
t
12
t
10
t
11
04820-003
Figure 3. Pixel Port and Control Output Timing
Rev. B | Page 9 of 104
ADV7181
ABSOLUTE MAXIMUM RATINGS
Table 6.
Parameter Rating
A
to GND 4 V
VDD
A
to AGND 4 V
VDD
D
to DGND 2.2 V
VDD
P
to AGND 2.2 V
VDD
D
to DGND 4 V
VDDIO
D
to AVDD –0.3 V to +0.3 V
VDDIO
P
to D
VDD
D
VDDIO
D
VDDIO
A
VDD
A
VDD
Digital Inputs Voltage to DGND –0.3 V to D
Digital Output Voltage to DGND –0.3 V to D
Analog Inputs to AGND AGND – 0.3 V to A
Maximum Junction Temperature
(T
Storage Temperature Range –65°C to +150°C
Infrared Reflow Soldering (20 s) 260°C
–0.3 V to +0.3 V
VDD
– P
–0.3 V to +2 V
VDD
– D
–0.3 V to +2 V
VDD
– P
–0.3 V to +2 V
VDD
– D
–0.3 V to +2 V
VDD
max)
J
150°C
VDDIO
VDDIO
+ 0.3 V
+ 0.3 V
+ 0.3 V
VDD
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods may
affect device reliability.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the
human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
4, 11 DVDDIO P Digital I/O Supply Voltage (3.3 V).
23, 58 DVDD P Digital Core Supply Voltage (1.8 V).
40 AVDD P Analog Supply Voltage (3.3 V).
31 PVDD P PLL Supply Voltage (1.8 V).
35, 36, 46–49 AIN1–AIN6 I Analog Video Input Channels.
1, 12, 13, 27, 28, 33,
NC No Connect Pins.
50, 55, 56
26, 25, 19, 18, 17,
P0–P15 O Video Pixel Output Port.
16, 15, 14, 8, 7, 6, 5,
62, 61, 60, 59
2 HS O Horizontal Synchronization Output Signal.
64 VS O Vertical Synchronization Output Signal.
63 FIELD O Field Synchronization Output Signal.
53 SDA I/O I2C Port Serial Data Input/Output Pin.
54 SCLK I I2C Port Serial Clock Input (Max Clock Rate of 400 kHz).
52 ALSB I
This pin selects the I
2
C address for the ADV7181. ALSB set to a Logic 0 sets the address for a
write as 0x40; for ALSB set to a logic high, the address selected is 0x42.
51
RESET
I
System Reset Input, Active Low. A minimum low reset pulse width of 5 ms is required to
reset the ADV7181 circuitry.
20 LLC O
This is a line-locked output clock for the pixel data output by the ADV7181. Nominally
27 MHz, but varies up or down according to video line length.
22 XTAL I
This is the input pin for the 27 MHz crystal, or can be overdriven by an external 3.3 V,
27 MHz clock oscillator source. In crystal mode, the crystal must be a fundamental crystal.
04820-004
Rev. B | Page 11 of 104
ADV7181
Pin No. Mnemonic Type Function
21 XTAL1 O
29
30 ELPF I
9 SFL O
41 REFOUT O
42 CML O
38, 39 CAPY1, CAPY2 I
44 CAPC2 I
PWRDN
I
This pin should be connected to the 27 MHz crystal or left as a no connect if an external
3.3 V, 27 MHz clock oscillator source is used to clock the ADV7181. In crystal mode, the
crystal must be a fundamental crystal.
A logic low on this pin places the ADV7181 in a power-down mode. Refer to the I2C Control
Register Map section for more options on power-down modes for the ADV7181.
The recommended external loop filter must be connected to this ELPF pin, as shown in
Figure 42.
Subcarrier Frequency Lock. This pin contains a serial output stream that can be used to lock
the subcarrier frequency when this decoder is connected to any Analog Devices digital
video encoder.
Internal Voltage Reference Output. Refer to Figure 42 for a recommended capacitor
network for this pin.
Common-Mode Level for the Internal ADCs. Refer to Figure 42 for a recommended
capacitor network for this pin.
ADC’s Capacitor Network. Refer to Figure 42 for a recommended capacitor network for
this pin.
ADC’s Capacitor Network. Refer to Figure 42 for a recommended capacitor network for
this pin.
Rev. B | Page 12 of 104
ADV7181
ANALOG FRONT END
ADC_SW_MAN_EN
AIN5
AIN6
AIN3
AIN4
AIN1
AIN2
AIN2
AIN1
AIN4
AIN3
AIN6
AIN5
AIN4
AIN3
AIN6
AIN5
AIN6
AIN5
ADC0_SW[3:0]
ADC0
ADC1_SW[3:0]
ADC1
ADC0_SW[3:0]
Figure 5. Internal Pin Connections
There are two key steps to configure the ADV7181 to correctly
decode the input video. Descriptions of these steps follow.
•The analog input muxing section must be configured to
correctly route the video from the analog input pins to the
correct set of ADCs.
•The standard definition processor block, which decodes
the digital data, should be configured to process either
CVBS, YC, or YPrPb.
ANALOG INPUT MUXING
The ADV7181 has an integrated analog muxing section that
allows more than one source of video signal to be connected to
the decoder. Figure 5 outlines the overall structure of the input
muxing provided in the ADV7181.
A maximum of six CVBS inputs can be connected and decoded
by the ADV7181. As seen in the Pin Configuration and
Function Description section, these analog input pins lie in
close proximity to one another. This calls for a careful design of
the PCB layout, for example, ground shielding between all
signals routed through tracks that are physically close together.
It is strongly recommended to connect any unused analog input
pins to AGND to act as a shield.
To configure the ADV7181 analog muxing section, the user
must select the analog input (AIN1–AIN6) that is to be
processed by each ADC. SETADC_sw_man_en must be set to 1
to enable the muxing blocks to be configured. The three mux
sections are controlled by the signal buses ADC0/1/2_sw[3:0].
Table 8 explains the control words used.
The input signal that contains the timing information (H/V
syncs) must be processed by ADC0. For example, in YC input
configuration, ADC0 should be connected to the Y channel and
ADC1 to the C channel. In cases where one or more ADCs are
not used to process video, for example, CVBS input, the idle
ADCs should be powered down, (see the ADC Power-Down
Control section).
Restrictions are imposed on the channel routing by the analog
signal routing inside the IC; every input pin cannot be routed to
each ADC. Refer to Table 8 for an overview on the routing
capabilities inside the chip.
Rev. B | Page 13 of 104
ADV7181
Table 8. Manual Mux Settings for All ADCs
SETADC_sw_man_en = 1
ADC0_sw[3:0] ADC0 Connected To: ADC1_sw[3:0] ADC1 Connected To: ADC2_sw[3:0] ADC2 Connected To:
0000 No Connection 0000 No Connection 0000 No Connection
0001 AIN2 0001 No Connection 0001 No Connection
0010 No Connection 0010 No Connection 0010 No Connection
0011 No Connection 0011 No Connection 0011 No Connection
0100 AIN4 0100 AIN4 0100 No Connection
0101 AIN6 0101 AIN6 0101 AIN6
0110 No Connection 0110 No Connection 0110 No Connection
0111 No Connection 0111 No Connection 0111 No Connection
1000 No Connection 1000 No Connection 1000 No Connection
1001 AIN1 1001 No Connection 1001 No Connection
1010 No Connection 1010 No Connection 1010 No Connection
1011 No Connection 1011 No Connection 1011 No Connection
1100 AIN3 1100 AIN3 1100 No Connection
1101 AIN5 1101 AIN5 1101 AIN5
1110 No Connection 1110 No Connection 1110 No Connection
1111 No Connection 1111 No Connection 1111 No Connection
CONNECTING
ANALOG SIGNALS
TO ADV7181
INSEL[3:0] Input Selection, Address 0x00 [3:0]
The INSEL bits allow the user to select the input format. It
SET INSEL[3:0] TO
CONFIGURE ADV7181 TO
DECODE VIDEO FORMAT:
CVBS: 0000
YC: 0110
YPrPb: 1001
CONFIGURE ADC INPUTS USING
MUXING CONTROL BITS
(ADC_sw_man_en,
ADC0_sw,adc1_sw, ADC2_sw)
Figure 6. Input Muxing Overview
04820-006
configures the Standard Definition Processor core to process
CVBS (Comp), S-Video (Y/C), or Component (YPbPr) format.
Table 9. Standard Definition Processor Format Selection,
INSEL[3:0]
INSEL[3:0] Video Format
0000 Composite
0110 YC
1001 YPrPb
Rev. B | Page 14 of 104
ADV7181
GLOBAL CONTROL REGISTERS
Register control bits listed in this section affect the whole chip.
POWER-SAVE MODES
Power-Down
PDBP, Address 0x0F [2]
There are two ways to shut down the digital core of the
ADV7181: a pin (
PWRDN
PDBP controls which of the two has the higher priority. The
default is to give the pin (
user to have the ADV7181 powered down by default.
Table 10. PDBP Function
PDBP Description
0 (default)
1 Bit has priority (pin is disregarded).
Digital core power controlled by the PWRDN
(bit is disregarded).
PWRDN, Address 0x0F [5]
Setting the PWRDN bit switches the ADV7181 into a chip-wide
power-down mode. The power-down stops the clock from
entering the digital section of the chip, thereby freezing its
2
operation. No I
C bits are lost during power-down. The
PWRDN bit also affects the analog blocks and switches them
into low current modes. The I
and remains operational in power-down mode.
The ADV7181 leaves the power-down state if the PWRDN bit is
2
set to 0 (via I
C), or if the overall part is reset using the
pin.
) and a bit (PWRDN see below). The
PWRDN
) priority. This allows the
2
C interface itself is unaffected,
pin
RESET
PWRDN_ADC_0, Address 0x3A [3]
Table 12. PWRDN_ADC_0 Function
PWRDN_ADC_0 Description
0 (default) ADC normal operation.
1 Power down ADC 0.
PWRDN_ADC_1, Address 0x3A [2]
Table 13. PWRDN_ADC_1 Function
PWRDN_ADC_1 Description
0 (default) ADC normal operation.
1 Power down ADC 1.
PWRDN_ADC_2, Address 0x3A [1]
Table 14. PWRDN_ADC_2 Function
PWRDN_ADC_2 Description
0 (default) ADC normal operation.
1 Power down ADC 2.
RESET CONTROL
Chip Reset (RES), Address 0x0F [7]
Setting this bit, equivalent to controlling the
ADV7181, issues a full chip reset. All I
their default values. (Some register bits do not have a reset value
specified. They keep their last written value. Those bits are
marked as having a reset value of x in the register table.) After
the reset sequence, the part immediately starts to acquire the
incoming video signal.
RESET
2
C registers are reset to
pin on the
PDBP must be set to 1 for the PWRDN bit to power down the
ADV7181.
Table 11. PWRDN Function
PWRDN Description
0 (default) Chip operational.
1 ADV7181 in chip-wide power-down.
ADC Power-Down Control
The ADV7181 contains three 9-bit ADCs (ADC 0, ADC 1, and
ADC 2). If required, it is possible to power down each ADC
individually.
When should the ADCs be powered down?
•CVBS mode. ADC 1 and ADC 2 should be powered down
to save on power consumption.
•S-Video mode. ADC 2 should be powered down to save on
power consumption.
Rev. B | Page 15 of 104
Notes
•After setting the RES bit (or initiating a reset via the pin),
the part returns to the default mode of operation with
2
respect to its primary mode of operation. All I
C bits are
loaded with their default values, making this bit selfclearing.
•Executing a software reset takes approximately 2 ms.
However, it is recommended to wait 5 ms before further
2
C writes are performed.
I
2
•The I
C master controller receives a no acknowledge
condition on the ninth clock cycle when chip reset is
implemented. See the MPU Port Description section.
Table 15. RES Function
RES Description
0 (default) Normal operation.
1 Start reset sequence.
ADV7181
GLOBAL PIN CONTROL
Three-State Output Drivers
TOD, Address 0x03 [6]
This bit allows the user to three-state the output drivers of the
ADV7181.
Upon setting the TOD bit, the P15–P0, HS, VS, FIELD, and SFL
pins are three-stated.
The timing pins (HS/VS/FIELD) can be forced active via the
TIM_OE bit. For more information on three-state control, refer
to the following sections:
• Three-State LLC Driver
• Timing Signals Output Enable
Individual drive strength controls are provided via the
DR_STR_XX bits.
This bit allows the output drivers for the LLC pin of the
ADV7181 to be three-stated. For more information on threestate control, refer to the following sections:
• Three-State Output Drivers
• Timing Signals Output Enable
Timing Signals Output Enable
TIM_OE, Address 0x04 [3]
The TIM_OE bit should be regarded as an addition to the TOD
bit. Setting it high forces the output drivers for HS, VS, and
FIELD into the active (that is, driving) state even if the TOD bit
is set. If set to low, the HS, VS, and FIELD pins are three-stated
depending on the TOD bit. This functionality is useful if the
decoder is to be used as a timing generator only. This may be
the case if only the timing signals are to be extracted from an
incoming signal, or if the part is in free-run mode where a
separate chip can output, for instance, a company logo.
For more information on three-state control, refer to the
following sections:
• Three-State Output Drivers
• Three-State LLC Driver
Individual drive strength controls are provided via the
DR_STR_XX bits.
Table 18. TIM_OE Function
TIM_OE Description
0 (default)
1
HS, VS, FIELD three-stated according to the
TOD bit.
HS, VS, FIELD are forced active all the time. The
DR_STR_S[1:0] setting determines drive
strength.
Drive Strength Selection (Data)
DR_STR[1:0] Address 0x04 [5:4]
For EMC and crosstalk reasons, it may be desirable to
strengthen or weaken the drive strength of the output drivers.
The DR_STR[1:0] bits affect the P[15:0] output drivers.
Individual drive strength controls are provided via the
DR_STR_XX bits.
Table 17. TRI_LLC Function
TRI_LLC Description
0 (default)
1 LLC pin drivers three-stated.
LLC pin drivers working according to the
DR_STR_C[1:0] setting (pin enabled).
For more information on three-state control, refer to the
following sections:
• Drive Strength Selection (Clock)
• Drive Strength Selection (Sync)
Table 19. DR_STR Function
DR_STR[1:0] Description
00 Low drive strength (1×).
01 (default) Medium low drive strength (2×).
10 Medium high drive strength (3×).
11 High drive strength (4×).
Rev. B | Page 16 of 104
ADV7181
Drive Strength Selection (Clock)
Enable Subcarrier Frequency Lock Pin
DR_STR_C[1:0] Address 0x0E [3:2]
The DR_STR_C[1:0] bits can be used to select the strength of
the clock signal output driver (LLC pin). For more information,
refer to the following sections:
• Drive Strength Selection (Sync)
• Drive Strength Selection (Data)
Table 20. DR_STR_C Function
DR_STR_C[1:0] Description
00 Low drive strength (1×).
01 (default) Medium low drive strength (2×).
10 Medium high drive strength (3×).
11 High drive strength (4×).
Drive Strength Selection (Sync)
DR_STR_S[1:0] Address 0x0E [1:0]
The DR_STR_S[1:0] bits allow the user to select the strength of
the synchronization signals with which HS, VS, and F are
driven. For more information, refer to the following sections:
• Drive Strength Selection (Clock)
• Drive Strength Selection (Data)
Table 21. DR_STR_S Function
DR_STR_S[1:0] Description
00 Low drive strength (1×).
01 (default) Medium low drive strength (2×).
10 Medium high drive strength (3×).
11 High drive strength (4×).
EN_SFL_PIN Address 0x04 [1]
The EN_SFL_PIN bit enables the output of subcarrier lock
information (also known as GenLock) from the ADV7181 to an
encoder in a decoder-encoder back-to-back arrangement.
Table 22. EN_SFL_PIN
EN_SFL_PIN Description
0 (default) Subcarrier frequency lock output is disabled.
1
Subcarrier frequency lock information is
presented on the SFL pin.
Polarity LLC Pin
PCLK Address 0x37 [0]
The polarity of the clock that leaves the ADV7181 via the LLC
pin can be inverted using the PCLK bit.
Changing the polarity of the LLC clock output may be
necessary to meet the setup-and-hold time expectations of
follow-on chips.
Table 23. PCLK Function
PCLK Description
0 Invert LLC output polarity.
1 (default)
LLC output polarity normal (as per the Timing
Diagrams).
Rev. B | Page 17 of 104
ADV7181
GLOBAL STATUS REGISTERS
Four registers provide summary information about the video
decoder. The IDENT register allows the user to identify the
revision code of the ADV7181. The other three registers contain
status bits from the ADV7181.
IDENTIFICATION
Depending on the setting of the FSCLE bit, the Status[0] and
Status[1] are based solely on horizontal timing info or on the
horizontal timing and lock status of the color subcarrier. See the
FSCLE Fsc Lock Enable, Address 0x51 [7] section.
Autodetection Result
IDENT[7:0] Address 0x11 [7:0]
Provides identification of the revision of the ADV7181. Review
the list of IDENT code readback values for the various versions
shown in Table 24.
This read-only register provides information about the internal
status of the ADV7181.
See CIL[2:0] Count Into Lock, Address 0x51 [2:0] and COL[2:0]
Count Out of Lock, Address 0x51 [5:3] for information on the
timing.
Table 26. STATUS 1 Function
STATUS 1 [7:0] Bit Name Description
0 IN_LOCK In lock (right now).
1 LOST_LOCK Lost lock (since last read of this register).
2 FSC_LOCK Fsc locked (right now).
3 FOLLOW_PW AGC follows peak white algorithm.
4 AD_RESULT.0 Result of autodetection.
5 AD_RESULT.1 Result of autodetection.
6 AD_RESULT.2 Result of autodetection.
7 COL_KILL Color kill active.
AD_RESULT[2:0] Address 0x10 [6:4]
The AD_RESULT[2:0] bits report back on the findings from the
autodetection block. Consult the General Setup sec-tion for
more information on enabling the autodetection block, and the
Autodetection of SD Modes section to find out how to
configure it.
STATUS_2[7:0], Address 0x12 [7:0]
Table 27. STATUS 2 Function
STATUS 2 [7:0] Bit Name Description
0 MVCS DET Detected Macrovision color striping.
1 MVCS T3 Macrovision color striping protection. Conforms to Type 3 (if high), and Type 2 (if low).
2 MV_PS DET Detected Macrovision pseudo sync pulses.
3 MV_AGC DET Detected Macrovision AGC pulses.
4 LL_NSTD Line length is nonstandard.
5 FSC_NSTD Fsc frequency is nonstandard.
6 Reserved
7 Reserved
STATUS 3
STATUS_3[7:0], Address 0x13 [7:0]
Table 28. STATUS 3 Function
5 STD_FLD_LEN Field length is correct for currently selected video standard.
6 INTERLACED Interlaced video detected (field sequence found).
7 PAL_SW_LOCK Reliable sequence of swinging bursts detected.
ADV7181 outputs a blue screen (see the DEF_VAL_AUTO_EN Default Value Automatic
Enable, Address 0x0C [1] section).
Rev. B | Page 19 of 104
ADV7181
STANDARD DEFINITION PROCESSOR (SDP)
STANDARD DEFINITION PROCESSOR
DIGITIZED CVBS
DIGITIZED Y (YC)
DIGITIZED CVBS
DIGITIZED C (YC)
MACROVISION
DETECTION
LUMA
DIGITAL
FINE
CLAMP
CHROMA
DIGITAL
FINE
CLAMP
RECOVERY
CHROMA
DEMOD
F
SC
RECOVERY
VBI DATA
FILTER
EXTRACT
CHROMA
FILTER
AUTODETECTION
LUMA
SYNC
STANDARD
Figure 7. Block Diagram of the Standard Definition Processor
A block diagram of the ADV7181’s standard definition
processor is shown in Figure 7.
The SDP block can handle standard definition video in CVBS,
YC, and YPrPb formats. It can be divided into a luminance and
chrominance path. If the input video is of a composite type
(CVBS), both processing paths are fed with the CVBS input.
SD LUMA PATH
The input signal is processed by the following blocks:
•Digital Fine Clamp. This block uses a high precision
algorithm to clamp the video signal.
•Luma Filter Block. This block contains a luma decimation
filter (YAA) with a fixed response, and some shaping filters
(YSH) that have selectable responses.
•Luma Gain Control. The automatic gain control (AGC)
can operate on a variety of different modes, including gainbased on the depth of the horizontal sync pulse, peak white
mode, and fixed manual gain.
•Luma Resample. To correct for line-length errors as well as
dynamic line-length changes, the data is digitally
resampled.
•Luma 2D Comb. The two-dimensional comb filter
provides YC separation.
•AV Code Insertion. At this point, the decoded luma (Y)
signal is merged with the retrieved chroma values. AV
codes (as per ITU-R. BT-656) can be inserted.
GAIN
CONTROL
LINE
LENGTH
PREDICTOR
GAIN
CONTROL
SLLC
CONTROL
LUMA
RESAMPLE
RESAMPLE
CONTROL
CHROMA
RESAMPLE
LUMA
2D COMB
CHROMA
2D COMB
AV
CODE
INSERTION
VIDEO DATA
OUTPUT
MEASUREMENT
BLOCK (= >1
VIDEO DATA
PROCESSING
BLOCK
2
C)
04820-007
SD CHROMA PATH
The input signal is processed by the following blocks:
•Digital Fine Clamp. This block uses a high precision
algorithm to clamp the video signal.
•Chroma Demodulation. This block uses a color subcarrier
(Fsc) recovery unit to regenerate the color subcarrier for
any modulated chroma scheme. The demodulation block
then performs an AM demodulation for PAL and NTSC,
and an FM demodulation for SECAM.
•Chroma Filter Block. This block contains a chroma
decimation filter (CAA) with a fixed response, and some
shaping filters (CSH) that have selectable responses.
•Gain Control. Automatic gain control (AGC) can operate
on several different modes, including gain based on the
color subcarrier’s amplitude, gain based on the depth of the
horizontal sync pulse on the luma channel, or fixed manual
gain.
•Chroma Resample. The chroma data is digitally resampled
to keep it perfectly aligned with the luma data. The
resampling is done to correct for static and dynamic linelength errors of the incoming video signal.
•Chroma 2D Comb. The two-dimensional, 5-line,
superadaptive comb filter provides high quality YC
separation in case the input signal is CVBS.
•AV Code Insertion. At this point, the demodulated chroma
(Cr and Cb) signal is merged with the retrieved luma
values. AV codes (as per ITU-R. BT-656) can be inserted.
Rev. B | Page 20 of 104
ADV7181
SYNC PROCESSING
The ADV7181 extracts syncs embedded in the video data
stream. There is currently no support for external HS/VS
inputs. The sync extraction has been optimized to support
imperfect video sources, for example, videocassette recorders
with head switches. The actual algorithm used employs a coarse
detection based on a threshold crossing followed by a more
detailed detection using an adaptive interpolation algorithm.
The raw sync information is sent to a line-length measurement
and prediction block. The output is then used to drive the
digital resampling section to ensure that the ADV7181 outputs
720 active pixels per line.
The sync processing on the ADV7181 includes two specialized
postprocessing blocks that filter and condition the raw sync
information retrieved from the digitized analog video.
•VSYNC processor. This block provides extra filtering of the
detected VSYNCs to give improved vertical lock.
•HSYNC processor. The HSYNC processor is designed to
filter incoming HSYNCs that have been corrupted by
noise, providing much improved performance for video
signals with stable time base but poor SNR.
VBI DATA RECOVERY
The ADV7181 can retrieve the following information from the
input video:
• Wide-screen signaling (WSS)
• Copy generation management system (CGMS)
• Closed caption (CC)
• Macrovision protection presence
• EDTV data
• Gemstar-compatible data slicing
The ADV7181 is capable of automatically detecting the
incoming video standard with respect to color subcarrier
frequency, field rate, and line rate.
It can configure itself to support PAL-BGHID, PAL-M/N,
PAL-combination N, NTSC-M, NTSC-J, SECAM 50 Hz/60 Hz,
NTSC4.43, and PAL60.
GENERAL SETUP
Video Standard Selection
The VID_SEL[3:0] register allows the user to force the digital
core into a specific video standard. Under normal circumstances,
this should not be necessary. The VID_SEL[3:0] bits default to
an autodetection mode that supports PAL, NTSC, SECAM, and
variants thereof.
Refer to the Autodetection of SD Modes section for more
information on the autodetection system.
Autodetection of SD Modes
In order to guide the autodetect system of the ADV7181,
individual enable bits are provided for each of the supported
video standards. Setting the relevant bit to 0 inhibits the
standard from being detected automatically. Instead, the system
picks the closest of the remaining enabled standards. The results
of the autodetection can be read back via the status registers.
See the Global Status Registers section for more information.
Table 29. VID_SEL Function
VID_SEL[3:0]
Address 0x00 [7:4] Description
0000 (default)
0001
0010
0011
0100 NTSC J (1)
0101 NTSC M (1).
0110 PAL60.
0111 NTSC4.43 (1).
1000 PAL BGHID.
1001 PAL N (= PAL BGHID (with pedestal)).
1010 PAL M (without pedestal).
1011 PAL M.
1100 PAL combination N.
1101 PAL combination N (with pedestal).
1110 SECAM.
1111 SECAM (with pedestal).
Autodetect (PAL BGHID) <–> NTSC J
(no pedestal), SECAM.
Autodetect (PAL BGHID) <–> NTSC M
(pedestal), SECAM.
Autodetect (PAL N) <–> NTSC J (no
pedestal), SECAM.
Autodetect (PAL N) <–> NTSC M
(pedestal), SECAM.
Rev. B | Page 21 of 104
ADV7181
AD_SEC525_EN Enable Autodetection of SECAM 525
Line Video, Address 0x07 [7]
Table 30. AD_SEC525_EN Function
AD_SEC525_EN Description
0 (default)
1 Enable the detection.
AD_SECAM_EN Enable Autodetection of SECAM,
Address 0x07 [6]
Table 31. AD_SECAM_EN Function
AD_SECAM_EN Description
0 Disable the autodetection of SECAM.
1 (default) Enable the detection.
AD_N443_EN Enable Autodetection of NTSC443,
Address 0x07 [5]
Table 32. AD_N443_EN Function
AD_N443_EN Description
0
1 (default) Enable the detection.
AD_P60_EN Enable Autodetection of PAL60,
Address 0x07 [4]
Table 33. AD_P60_EN Function
AD_P60_EN Description
0
1 (default) Enable the detection.
AD_PALN_EN Enable Autodetection of PAL N,
Address 0x07 [3]
Table 34. AD_PALN_EN Function
AD_PALN_EN Description
0 Disable the detection of the PAL N standard.
1 (default) Enable the detection.
AD_PALM_EN Enable Autodetection of PAL M,
Address 0x07 [2]
Table 35. AD_PALM_EN Function
AD_PALM_EN Description
0 Disable the autodetection of PAL M.
1 (default) Enable the detection.
Disable the autodetection of a 525-line
system with a SECAM style, FM-modulated
color component.
Disable the autodetection of NTSC style
systems with a 4.43 MHz color subcarrier.
Disable the autodetection of PAL systems
with a 60 Hz field rate.
AD_NTSC_EN Enable Autodetection of NTSC,
Address 0x07 [1]
Table 36. AD_NTSC_EN Function
AD_NTSC_EN Description
0 Disable the detection of standard NTSC.
1 (default) Enable the detection.
AD_PAL_EN Enable Autodetection of PAL,
Address 0x07 [0]
Table 37. AD_PAL_EN Function
AD_PAL_EN Description
0 Disable the detection of standard PAL.
1 (default) Enable the detection.
SFL_INV Subcarrier Frequency Lock Inversion
This bit controls the behavior of the PAL switch bit in the SFL
(GenLock Telegram) data stream. It was implemented to solve
some compatibility issues with video encoders. It solves two
problems:
•The PAL switch bit is only meaningful in PAL. Some
encoders (including Analog Devices encoders) also look
at the state of this bit in NTSC.
•There was a design change in Analog Devices encoders
from ADV717x to ADV719x. The older versions used the
SFL (GenLock Telegram) bit directly, while the later ones
invert the bit prior to using it. This is because the inversion
compensated for the 1-line delay of an SFL (GenLock
Telegram) transmission.
As a result:
•ADV717x encoders need the PAL switch bit in the SFL
(GenLock Telegram) to be 1 for NTSC to work.
•ADV7190/ADV7191/ADV7194 encoders need the PAL
switch bit in the SFL to be 0 to work in NTSC.
If the state of the PAL switch bit is wrong, a 180°phase shift
occurs.
In a decoder/encoder back-to-back system in which SFL is used,
this bit must be set up properly for the specific encoder used.
Table 38. SFL_INV Function
SFL_INV
Address 0x41 [6]
0
1 (default)
Description
SFL-compatible with ADV7190/ADV7191/
ADV7194 encoders.
SFL-compatible with ADV717x/ADV7173x
encoders.
Rev. B | Page 22 of 104
ADV7181
Lock Related Controls
Lock information is presented to the user through Bits [1:0] of
the Status 1 register. See the STATUS_1[7:0] Address 0x10 [7:0]
section. Figure 8 outlines the signal flow and the controls
available to influence the way the lock status information is
generated.
SRLS Select Raw Lock Signal, Address 0x51 [6]
Using the SRLS bit, the user can choose between two sources for
determining the lock status (per Bits [1:0] in the Status 1 register).
•The time_win signal is based on a line-to-line evaluation of
the horizontal synchronization pulse of the incoming
video. It reacts quite quickly.
•The free_run signal evaluates the properties of the
incoming video over several fields, and takes vertical
synchronization information into account.
Table 39. SRLS Function
SRLS Description
0 (default) Select the free_run signal.
1 Select the time_win signal.
FSCLE Fsc Lock Enable, Address 0x51 [7]
The FSCLE bit allows the user to choose whether or not the
status of the color subcarrier loop is taken into account when
the overall lock status is determined and presented via Bits [1:0]
in Status Register 1. This bit must be set to 0 when operating the
ADV7181 in YPrPb component mode in order to generate a
reliable HLOCK status bit.
Table 40. FSCLE Function
FSCLE Description
0
Overall lock status only dependent on
horizontal sync lock.
1 (default)
Overall lock status dependent on horizontal
sync lock and Fsc Lock.
SELECT THE RAW LOCK SIGNAL
SRLS
TIME_WIN
FREE_RUN
F
LOCK
SC
1
0
0
COUNTER INTO LOCK
COUNTER OUT OF LOCK
1
CIL[2:0] Count Into Lock, Address 0x51 [2:0]
CIL[2:0] determine the number of consecutive lines for which
the into lock condition must be true before the system switches
into the locked state, and reports this via Status 0 [1:0].
Table 41. CIL Function
CIL[2:0] Description (Count Value in Lines of Video)
COL[2:0] determine the number of consecutive lines for which
the out of lock condition must be true before the system switches
into the unlocked state, and reports this via Status 0 [1:0].
Table 42. COL Function
COL[2:0] Description (Count Value in Lines of Video)
The following registers provide user control over the picture
appearance, including control of the active data in the event of
video being lost. They are independent of any other controls.
For instance, brightness control is independent from picture
clamping, although both controls affect the signal’s dc level.
This register allows the user to control the gain of the Cr
channel only.
CON[7:0] Contrast Adjust, Address 0x08 [7:0]
This register allows the user to adjust the contrast of the picture.
Table 43. CON Function
CON[7:0] Description
(Adjust Contrast of the Picture)
0x80 (default) Gain on luma channel = 1.
0x00 Gain on luma channel = 0.
0xFF Gain on luma channel = 2.
SAT[7:0] Saturation Adjust, Address 0x09 [7:0]
The user can adjust the saturation of the color output using this
register.
ADI encourages users not to use the SAT[7:0] register, which
may be removed in future revisions of the ADV7181. Instead,
the SD_SAT_Cb and SD_SAT_Cr registers should be used.
Table 44. SAT Function
SAT[7:0] Description
(Adjust Saturation of the Picture)
0x80 (default) Chroma gain = 0 dB.
0x00 Chroma gain = –42 dB.
0xFF Chroma gain = 6 dB.
This register allows the user to control the gain of the Cb
channel only.
For this register to be active, SAT[7:0] must be programmed
with its default value of 0x80. If SAT[7:0] is programmed with a
different value, SD_SAT_Cb[7:0] and SD_SAT_Cr[7:0] are
inactive.
Table 45. SD_SAT_Cb Function
Description
SD_SAT_Cb[7:0]
0x80 (defualt) Gain on Cb channel = 0 dB.
0x00 Gain on Cb channel = –42 dB.
0xFF Gain on Cb channel = +6 dB.
(Adjust Saturation of the Picture)
For this register to be active, SAT[7:0] must be programmed
with its default value of 0x80. If SAT[7:0] is programmed with a
different value, SD_SAT_Cb[7:0] and SD_SAT_Cr[7:0] are
inactive.
Table 46. SD_SAT_Cr Function
Description
SD_SAT_Cr[7:0]
0x80 (default) Gain on Cr channel = 0 dB.
0x00 Gain on Cr channel = –42 dB.
0xFF Gain on Cr channel = +6 dB.
This register allows the user to select an offset for the Cr
channel only. There is a functional overlap with the Hue [7:0]
register.
Table 48. SD_OFF_Cr Function
Description
(Adjust Hue of the Picture by Selecting
SD_OFF_Cr[7:0]
0x80 (default) 0 offset applied to the Cb channel.
0x00 –312 mV offset applied to the Cr channel.
0xFF +312 mV offset applied to the Cr channel.
an Offset for Data on Cr Channel)
Rev. B | Page 24 of 104
ADV7181
BRI[7:0] Brightness Adjust, Address 0x0A [7:0]
This register controls the brightness of the video signal through
the ADV7181.
Table 49. BRI Function
BRI[7:0] Description
(Adjust Brightness of the Picture)
0x00 (default) Offset of the luma channel = 0IRE.
0x7F Offset of the luma channel = 100IRE.
0x80 Offset of the luma channel = –100IRE.
Table 51. DEF_Y Function
DEF_Y[5:0] Description
0x0D (blue) (default) Default value of Y.
DEF_C[7:0] Default Value C, Address 0x0D [7:0]
The DEF_C[7:0] register complements the DEF_Y[5:0] value.
It defines the 4 MSBs of Cr and Cb values to be output if
•The DEF_VAL_AUTO_EN bit is set to high and the
ADV7181 can’t lock to the input video (automatic mode).
HUE[7:0] Hue Adjust, Address 0x0B [7:0]
This register contains the value for the color hue adjustment.
HUE[7:0] has a range of ±90°, with 0x00 equivalent to an
adjustment of 0°. The resolution of HUE[7:0] is 1 bit = 0.7°.
The hue adjustment value is fed into the AM color demodulation
block. Therefore, it only applies to video signals that contain
chroma information in the form of an AM modulated carrier
(CVBS or Y/C in PAL or NTSC). It does not affect SECAM and
does not work on component video inputs (YPrPb).
Table 50. HUE Function
HUE[7:0] Description(Adjust Hue of the Picture)
0x00 (default) Phase of the chroma signal = 0°.
0x7F Phase of the chroma signal = +90°.
0x80 Phase of the chroma signal = –90°.
DEF_Y[5:0] Default Value Y, Address 0x0C [7:2]
When the ADV7181 loses lock on the incoming video signal or
when there is no input signal, the DEF_Y[5:0] register allows
the user to specify a default luma value to be output.
This value is used under the following conditions:
•If DEF_VAL_AUTO_EN bit is set to high and the
ADV7181 lost lock to the input video signal. This is the
intended mode of operation (automatic mode).
•The DEF_VAL_EN bit is set, regardless of the lock status of
the video decoder. This is a forced mode that may be useful
during configuration.
The DEF_Y[5:0] values define the 6 MSBs of the output video.
The remaining LSBs are padded with 0s. For example, in 8-bit
mode, the output is Y[7:0] = {DEF_Y[5:0], 0, 0}.
•DEF_VAL_EN bit is set to high (forced output).
The data that is finally output from the ADV7181 for the
chroma side is Cr[7:0] = {DEF_C[7:4], 0, 0, 0, 0}, Cb[7:0] =
{DEF_C[3:0], 0, 0, 0, 0}.
Table 52. DEF_C Function
DEF_C[7:0] Description
0x7C (blue) (default) Default values for Cr and Cb.
DEF_VAL_EN Default Value Enable, Address 0x0C [0]
This bit forces the use of the default values for Y, Cr, and Cb.
Refer to the descriptions for DEF_Y and DEF_C for additional
information. The decoder also outputs a stable 27 MHz clock,
HS, and VS in this mode.
Table 53. DEF_VAL_EN Function
DEF_VAL_EN Description
0 (default)
1
Don't force the use of default Y, Cr, and
Cb values. Output colors dependent on
DEF_VAL_AUTO_EN.
Always use default Y, Cr, and Cb values.
Override picture data even if the video
decoder is locked.
DEF_VAL_AUTO_EN Default Value Automatic Enable,
Address 0x0C [1]
This bit enables the automatic usage of the default values for Y,
Cr, and Cb when the ADV7181 cannot lock to the video signal.
Table 54. DEF_VAL_AUTO_EN Function
DEF_VAL_AUTO_EN Description
0
1 (default)
Don't use default Y, Cr, and Cb values. If
unlocked, output noise.
Use default Y, Cr, and Cb values when
the decoder loses lock.
Rev. B | Page 25 of 104
ADV7181
A
G
CLAMP OPERATION
FINE
CURRENT
SOURCES
COARSE
CURRENT
SOURCES
NALO
VIDEO
INPUT
ADC
Figure 9. Clamping Overview
The input video is ac-coupled into the ADV7181 through a
0.1 µF capacitor. It is recommended that the range of the input
video signal is 0.5 V to 1.6 V (typically 1 V p-p). If the signal
exceeds this range, it cannot be processed correctly in the
decoder. Since the input signal is ac-coupled into the decoder,
its dc value needs to be restored. This process is referred to as
clamping the video. This section explains the general process of
clamping on the ADV7181 and shows the different ways in
which a user can configure its behavior.
The ADV7181 uses a combination of current sources and a
digital processing block for clamping, as shown in Figure 9.
The analog processing channel shown is replicated three times
inside the IC. While only one single channel (and only one
ADC) would be needed for a CVBS signal, two independent
channels are needed for YC (S-VHS) type signals, and three
independent channels are needed to allow component signals
(YPrPb) to be processed.
The clamping can be divided into two sections:
•Clamping before the ADC (analog domain): current
sources.
DATA
PRE
PROCESSOR
(DPP)
CLAMP CONTROL
SDP
WITH DIGITAL
FINE CLAMP
04820-009
The clamping scheme has to complete two tasks: it must be able
to acquire a newly connected video signal with a completely
unknown dc level, and it must maintain the dc level during
normal operation.
For a fast acquiring of an unknown video signal, the large
current clamps may be activated. (It is assumed that the
amplitude of the video signal at this point is of a nominal
value.) Control of the coarse and fine current clamp parameters
is performed automatically by the decoder.
Standard definition video signals may have excessive noise on
them. In particular, CVBS signals transmitted by terrestrial
broadcast and demodulated using a tuner usually show very
large levels of noise (>100 mV). A voltage clamp would be
unsuitable for this type of video signal. Instead, the ADV7181
employs a set of four current sources that can cause coarse
(>0.5 mA) and fine (<0.1 mA) currents to flow into and away
from the high impedance node that carries the video signal (see
Figure 9).
2
The following sections describe the I
C signals that can be used
to influence the behavior of the clamping.
•Clamping after the ADC (digital domain): digital
processing block.
The ADCs can digitize an input signal only if it resides within
the ADC’s 1.6 V input voltage range. An input signal with a dc
level that is too large or too small is clipped at the top or bottom
of the ADC range.
The primary task of the analog clamping circuits is to ensure
that the video signal stays within the valid ADC input window
so the analog-to-digital conversion can take place. It is not necessary to clamp the input signal with a very high accuracy in the
analog domain as long as the video signal fits the ADC range.
After digitization, the digital fine clamp block corrects for any
remaining variations in dc level. Since the dc level of an input
video signal refers directly to the brightness of the picture
transmitted, it is important to perform a fine clamp with high
accuracy; otherwise, brightness variations may occur. Furthermore, dynamic changes in the dc level almost certainly lead to
visually objectionable artifacts, and must therefore be prohibited.
Rev. B | Page 26 of 104
Previous revisions of the ADV7181 had controls (FACL/FICL,
fast and fine clamp length) to allow configuration of the length
for which the coarse (fast) and fine current sources are switched
on. These controls were removed on the ADV7181-FT and
replaced by an adaptive scheme.
CCLEN Current Clamp Enable, Address 0x14 [4]
The current clamp enable bit allows the user to switch off the
current sources in the analog front end altogether. This may be
useful if the incoming analog video signal is clamped externally.
Table 55. CCLEN Function
CCLEN Description
0 Current sources switched off.
1 (default) Current sources enabled.
ADV7181
DCT[1:0] Digital Clamp Timing, Address 0x15 [6:5]
The Clamp Timing register determines the time constant of the
digital fine clamp circuitry. It is important to realize that the
digital fine clamp reacts very fast since it is supposed to
immediately correct any residual dc level error for the active
line. The time constant of the digital fine clamp must be much
quicker than the one from the analog blocks.
By default, the time constant of the digital fine clamp is adjusted
dynamically to suit the currently connected input signal.
Table 56. DCT Function
DCT[1:0] Description
00 Slow (TC = 1 sec).
01 Medium (TC = 0.5 sec).
10 (default) Fast (TC = 0.1 sec).
11
Determined by ADV7181 depending on video
parameters.
DCFE Digital Clamp Freeze Enable, Address 0x15 [4]
This register bit allows the user to freeze the digital clamp loop
at any time. It is intended for users who would like to do their
own clamping. Users should disable the current sources for
analog clamping via the appropriate register bits, wait until the
digital clamp loop settles, and then freeze it via the DCFE bit.
Table 57. DCFE Function
DCFE Description
0 (default) Digital clamp operational.
1 Digital clamp loop frozen.
LUMA FILTER
Data from the digital fine clamp block is processed by three sets
of filters. The data format at this point is CVBS for CVBS input
or luma only for Y/C and YPrPb input formats.
•Luma antialias filter (YAA). The ADV7181 receives video
at a rate of 27 MHz. (In the case of 4× oversampled video,
the ADCs sample at 54 MHz, and the first decimation is
performed inside the DPP filters. Therefore, the data rate
into the ADV7181 is always 27 MHz.) The ITU-R BT.601
recommends a sampling frequency of 13.5 MHz. The luma
antialias filter decimates the oversampled video using a
high quality, linear phase, low-pass filter that preserves the
luma signal while at the same time attenuating out-of-band
components. The luma antialias filter (YAA) has a fixed
response.
•Luma shaping filters (YSH). The shaping filter block is a
programmable low-pass filter with a wide variety of
responses. It can be used to selectively reduce the luma
video signal bandwidth (needed prior to scaling, for
example). For some video sources that contain high
frequency noise, reducing the bandwidth of the luma
signal improves visual picture quality. A follow-on video
compression stage may work more efficiently if the video is
low-pass filtered.
The ADV7181 allows selection of two responses for the
shaping filter: one that is used for good quality CVBS,
component, and S-VHS type sources, and a second for
nonstandard CVBS signals.
The YSH filter responses also include a set of notches for
PAL and NTSC. However, it is recommended to use the
comb filters for YC separation.
•Digital resampling filter. This block is used to allow dynamic
resampling of the video signal to alter parameters such as
the time base of a line of video. Fundamentally, the resampler is a set of low-pass filters. The actual response is chosen
by the system with no requirement for user intervention.
Figure 11 through Figure 14 show the overall response of all
filters together. Unless otherwise noted, the filters are set into a
typical wideband mode.
Y Shaping Filter
For input signals in CVBS format, the luma shaping filters play
an essential role in removing the chroma component from a
composite signal. YC separation must aim for best possible
crosstalk reduction while still retaining as much bandwidth
(especially on the luma component) as possible. High quality
YC separation can be achieved by using the internal comb filters
of the ADV7181. Comb filtering, however, relies on the
frequency relationship of the luma component (multiples of the
video line rate) and the color subcarrier (Fsc). For good quality
CVBS signals, this relationship is known; the comb filter
algorithms can be used to separate out luma and chroma with
high accuracy.
In the case of nonstandard video signals, the frequency
relationship may be disturbed and the comb filters may not be
able to remove all crosstalk artifacts in an optimum fashion
without the assistance of the shaping filter block.
An automatic mode is provided. Here, the ADV7181 evaluates
the quality of the incoming video signal and selects the filter
responses in accordance with the signal quality and video
standard. YFSM, WYSFMOVR, and WYSFM allow the user to
manually override the automatic decisions in part or in full.
Rev. B | Page 27 of 104
ADV7181
The luma shaping filter has three control registers:
•YSFM[4:0] allows the user to manually select a shaping
filter mode (applied to all video signals) or to enable an
automatic selection (depending on video quality and video
standard).
•WYSFMOVR allows the user to manually override the
WYSFM decision.
•WYSFM[4:0] allows the user to select a different shaping
filter mode for good quality CVBS, component (YPrPb),
and S-VHS (YC) input signals.
In automatic mode, the system preserves the maximum possible
bandwidth for good CVBS sources (since they can successfully
be combed) as well as for luma components of YPrPb and YC
sources, since they need not be combed. For poor quality
signals, the system selects from a set of proprietary shaping
filter responses that complements comb filter operation in order
to reduce visual artifacts.
The decisions of the control logic are shown in Figure 10.
YSFM[4:0] Y Shaping Filter Mode, Address 0x17 [4:0]
The Y shaping filter mode bits allow the user to select from a
wide range of low-pass and notch filters. When switched in
automatic mode, the filter is selected based on other register
selections, for example, detected video standard, as well as
properties extracted from the incoming video itself, for example,
qu a l it y, t i m e b as e s t a bi l it y. T h e automatic selection always picks
the widest possible bandwidth for the video input encountered.
•If the YSFM settings specify a filter (that is, YSFM is set to
values other than 00000 or 00001), the chosen filter is
applied to all video, regardless of its quality.
•In automatic selection mode, the notch filters are only used
for bad quality video signals. For all other video signals,
wideband filters are used.
WYSFMOVR Wideband Y Shaping Filter Override,
Address 0x18 [7]
Setting the WYSFMOVR bit enables the use of the
WYSFM[4:0] settings for good quality video signals. For more
information, refer to the general discussion of the luma shaping
filters in the Y Shaping Filter section and the flowchart shown
in Figure 10.
Table 58. WYSFMOVR Function
WYSFMOVR Description
0
Automatic selection of shaping filter for good
quality video signals.
1 (default) Enable manual override via WYSFM[4:0].
SET YSFM
YSFM IN AUTO MODE?
00000 OR 00001
WYSFMOVR
SELECT AUTOMATIC
WIDEBAND FILTER
USE YSFM SELECTED
FILTER REGARDLESS FOR
GOOD AND BAD VIDEO
04820-010
VIDEO
BADGOOD
AUTO SELECT LUMA
SHAPING FILTER TO
COMPLEMENT COMB
QUALITY
10
SELECT WIDEBAND
FILTER AS PER
WYSFM[4:0]
Figure 10. YSFM and WYSFM Control Flowchart
YESNO
Rev. B | Page 28 of 104
ADV7181
Table 59. YSFM Function
YSFM[4:0] Description
0'0000
Automatic selection including a wide notch
response (PAL/NTSC/SECAM)
0'0001
(default)
Automatic selection including a narrow notch
response (PAL/NTSC/SECAM)
0'0010 SVHS 1
0'0011 SVHS 2
0'0100 SVHS 3
0'0101 SVHS 4
0'0110 SVHS 5
0'0111 SVHS 6
0'1000 SVHS 7
0'1001 SVHS 8
0'1010 SVHS 9
0'1011 SVHS 10
0'1100 SVHS 11
0'1101 SVHS 12
0'1110 SVHS 13
0'1111 SVHS 14
1'0000 SVHS 15
1'0001 SVHS 16
1'0010 SVHS 17
1'0011 SVHS 18 (CCIR 601)
1'0100 PAL NN 1
1'0101 PAL NN 2
1'0110 PAL NN 3
1'0111 PAL WN 1
1'1000 PAL WN 2
1'1001 NTSC NN 1
1'1010 NTSC NN 2
1'1011 NTSC NN 3
1'1100 NTSC WN 1
1'1101 NTSC WN 2
1'1110 NTSC WN 3
1'1111 Reserved.
WYSFM[4:0] Wide Band Y Shaping Filter Mode,
Address 0x18 [4:0]
The WYSFM[4:0] bits allow the user to manually select a shaping
filter for good quality video signals, for example, CVBS with
stable time base, luma component of YPrPb, luma component
of YC. The WYSFM bits are only active if the WYSFMOVR bit
is set to 1. See the general discussion of the shaping filter
settings in the Y Shaping Filter section.
Table 60. WYSFM Function
WYSFM[4:0] Description
0'0000 Do not use
0'0001 Do not use
0'0010 SVHS 1
0'0011 SVHS 2
0'0100 SVHS 3
0'0101 SVHS 4
0'0110 SVHS 5
0'0111 SVHS 6
0'1000 SVHS 7
0'1001 SVHS 8
0'1010 SVHS 9
0'1011 SVHS 10
0'1100 SVHS 11
0'1101 SVHS 12
0'1110 SVHS 13
0'1111 SVHS 14
1'0000 SVHS 15
1'0001 SVHS 16
1'0010 SVHS 17
1'0011 (default) SVHS 18 (CCIR 601)
1'0100–1’1111 Do not use
COMBINED Y ANTIALIAS, S-VHS LOW-PASS FILTERS,
0
–10
–20
–30
–40
AMPLITUDE (dB)
–50
–60
–70
010864212
Figure 11. Y S-VHS Combined Responses
Y RESAMPLE
FREQUENCY (MHz)
04820-011
The filter plots in Figure 11 and Figure 22 show the
S-VHS 1 (narrowest) to S-VHS 18 (widest) shaping filter
settings. Figure 13 shows the PAL notch filter responses.
The NTSC-compatible notches are shown in Figure 14.
Rev. B | Page 29 of 104
ADV7181
–20
–40
–60
AMPLITUDE (dB)
–80
–100
–120
COMBINED Y ANTIALIAS, CCIR MODE SHAPING FILTER,
0
010864212
Y RESAMPLE
FREQUENCY (MHz)
Figure 12. Y S-VHS 18 Extra Wideband Filter (CCIR 601-Compliant)
COMBINED Y ANTIALIAS, PAL NOTCH FILTERS,
0
–10
–20
Y RESAMPLE
CHROMA FILTER
Data from the digital fine clamp block is processed by three sets
of filters. The data format at this point is CVBS for CVBS
inputs, chroma only for Y/C, or U/V interleaved for YPrPb
input formats.
•Chroma Anti-alias Filter (CAA). The ADV7181 over-
samples the CVBS by a factor of 2 and the Chroma/PrPb
by a factor of 4. A decimating filter (CAA) is used to
preserve the active video band and remove any out-ofband components. The CAA filter has a fixed response.
04820-012
•Chroma Shaping Filters (CSH). The shaping filter block
(CSH) can be programmed to perform a variety of lowpass responses. It can be used to selectively reduce the
bandwidth of the chroma signal for scaling or compression.
•Digital Resampling Filter. This block is used to allow
dynamic resampling of the video signal to alter parameters
such as the time base of a line of video. Fundamentally, the
resampler is a set of low-pass filters. The actual response is
chosen by the system with no requirement for user
intervention.
–30
The plots in Figure 15 show the overall response of all filters
together.
–40
AMPLITUDE (dB)
–50
–60
–70
010864212
FREQUENCY (MHz)
04820-013
Figure 13. Pal Notch Filter Respon se
COMBINED Y ANTIALIAS, NTSC NOTCH FILTERS,
0
–10
–20
–30
–40
AMPLITUDE (dB)
–50
–60
–70
010864212
Y RESAMPLE
FREQUENCY (MHz)
04820-014
Figure 14. NTSC Notch Filter Response
CSFM[2:0] C Shaping Filter Mode, Address 0x17 [7]
The C shaping filter mode bits allow the user to select from a
range of low-pass filters for the chrominance signal. When
switched into automatic mode, the widest filter is selected based
on the video standard/format and on user choice (see settings
000 and 001 in Table 61).
Figure 15 shows the responses of SH1 (narrowest) to SH5
(widest) in addition to the wideband mode (in red).
Rev. B | Page 30 of 104
ADV7181
0
–10
–20
–30
–40
ATTENUATION (dB)
–50
–60
0543216
COMBINED C ANTIALIAS, C SHAPING FILTER,
Figure 15. Chroma Shaping Filter Responses
C RESAMPLER
FREQUENCY (MHz)
04820-015
GAIN OPERATION
The gain control within the ADV7181 is done on a purely
digital basis. The input ADCs support a 9-bit range, mapped
into a 1.6 V analog voltage range. Gain correction takes place
after the digitization in the form of a digital multiplier.
There are several advantages of this architecture over the
commonly used PGA (programmable gain amplifier) before the
ADCs; among them is the fact that the gain is now completely
independent of supply, temperature, and process variations.
As shown in Figure 16, the ADV7181 can decode a video signal
as long as it fits into the ADC window. There are two components
ANALOG VOLTAGE
MAXIMUM
VOLTAGE
RANGE SUPPORTED BY ADC (1.6V RANGE FOR ADV7181)
to this: the amplitude of the input signal and the dc level it
resides on. The dc level is set by the clamping circuitry (see the
Clamp Operation section).
If the amplitude of the analog video signal is too high, clipping
may occur, resulting in visual artifacts. The analog input range
of the ADC, together with the clamp level, determines the
maximum supported amplitude of the video signal.
The minimum supported amplitude of the input video is
determined by the ADV7181’s ability to retrieve horizontal and
vertical timing and to lock to the color burst (if present).
There are two gain control units, one each for luma and chroma
data. Both can operate independently of each other. The
chroma unit, however, can also take its gain value from the
luma path.
Several AGC modes are possible; Table 62 summarizes them.
It is possible to freeze the automatic gain control loops. This
causes the loops to stop updating. The AGC determined gain
at the time of the freeze stays active until the loop is either
unfrozen or the gain mode of operation is changed.
The currently active gain from any of the modes can be read
back. Refer to the description of the dual-function manual gain
registers, LG[11:0] Luma Gain and CG[11:0] Chroma Gain, in
the Luma Gain and Chroma Gain sections.
SDP
(GAIN SELECTION ONLY)
GAIN
CONTROL
MINIMUM
VOLTAGE
CLAMP
LEVEL
DATA
ADC
Figure 16. Gain Control Overview
PRE
PROCESSOR
(DPP)
Table 62. AGC Modes
Input Video Type Luma Gain Chroma Gain
Any Manual gain luma. Manual gain chroma.
CVBS
Dependent on color burst amplitude. Dependent on horizontal sync depth.
Taken from luma path.
Peak White
Dependent on color burst amplitude.
Taken from luma path.
Y/C
Dependent on color burst amplitude. Dependent on horizontal sync depth.
Taken from luma path.
Peak White.
Dependent on color burst amplitude.
Taken from luma path.
YPrPb Dependent on horizontal sync depth. Taken from luma path.
Rev. B | Page 31 of 104
04820-016
ADV7181
(
≤
<
Luma Gain
LAGC[2:0] Luma Automatic Gain Control,
Address 0x2C [7:0]
The luma automatic gain control mode bits select the mode of
operation for the gain control in the luma path.
There are ADI internal parameters to customize the peak white
gain control. Contact ADI for more information.
LAGT[1:0] Luma Automatic Gain Timing, Address 0x2F [7:6]
The luma automatic gain timing register allows the user to
influence the tracking speed of the luminance automatic gain
control. This register has an effect only if the LAGC[2:0]
register is set to 001, 010, 011, or 100 (automatic gain control
modes).
If peak white AGC is enabled and active (see the
STATUS_1[7:0] Address 0x10 [7:0] section), the actual gain
update speed is dictated by the peak white AGC loop and, as a
result, the LAGT settings have no effect. As soon as the part
leaves peak white AGC, LAGT becomes relevant again.
AGC (blank level to sync tip). No override
through white peak.
AGC (blank level to sync tip). Automatic
override through white peak.
LG[11:0] Luma Gain, Address 0x2F [3:0]; Address 0x30 [7:0];
LMG[11:0] Luma Manual Gain, Address 0x2F [3:0];
Address 0x30 [7:0]
Luma gain [11:0] is a dual-function register:
•If written to, a desired manual luma gain can be
programmed. This gain becomes active if the LAGC[2:0]
mode is switched to manual fixed gain.
• Equation 1 shows how to calculate a desired gain.
• If read back, this register returns the current gain value.
Depending on the setting in the LAGC [2:0] bits, this is
one of the following values:
o Luma manual gain value (LAGC [2:0] set to luma
manual gain mode).
o Luma automatic gain value (LAGC [2:0] set to any of
the automatic modes).
Table 65. LG/LMG Function
LG[11:0]/LMG[11:0] Read/Write Description
LMG[11:0] = X Write
LG[11:0] Read Actually used gain
LG
=
GainLuma
_=
2048
Manual gain for luma
path
)
40950
2...0
(1)
Example
Program the ADV7181 into manual fixed gain mode with a
desired gain of 0.89
Use Equation 1 to convert the gain:
1.
0.89 × 2048 = 1822.72
Truncate to integer value:
The update speed for the peak white algorithm can be
customized by the use of internal parameters. Contact ADI
for more information.
4.
Luma Gain Control 1 [3:0] = 0x7
Luma Gain Control 2 [7:0] = 0x1E
Enable Manual Fixed Gain Mode:
5.
Set LAGC[2:0] to 000
Rev. B | Page 32 of 104
ADV7181
BETACAM Enable Betacam Levels, Address 0x01 [5]
If YPrPb data is routed through the ADV7181, the automatic
gain control modes can target different video input levels, as
outlined in Table 70. The BETACAM bit is valid only if the
input mode is YPrPb (component). The BETACAM bit sets
the target value for AGC operation.
A review of the following sections is useful:
SETADC_sw_man_en, Manual Input Muxing Enable,
•
Address C4 [7] to find how component video (YPrPb) can
be routed through the ADV7181.
•
Video Standard Selection to select the various standards,
for example, with and without pedestal.
The automatic gain control (AGC) algorithms adjust the levels
based on the setting of the BETACAM bit (see Table 66.).
Table 66. BETACAM Function
BETACAM Description
0 (default) Assuming YPrPb is selected as input format.
Selecting PAL with pedestal selects MII.
Selecting PAL without pedestal selects SMPTE.
Selecting NTSC with pedestal selects MII.
Selecting NTSC without pedestal selects SMPTE.
1 Assuming YPrPb is selected as input format.
Selecting PAL with pedestal selects BETACAM.
Selecting NTSC with pedestal selects BETACAM.
Selecting PAL without pedestal selects BETACAM
variant.
Selecting NTSC without pedestal selects BETACAM
variant.
PW_UPD Peak White Update, Address 0x2B [0]
The peak white and average video algorithms determine the
gain based on measurements taken from the active video. The
PW_UPD bit determines the rate of gain change. LAGC[2:0]
must be set to the appropriate mode to enable the peak white or
average video mode in the first place. For more information,
refer to the LAGC[2:0] Luma Automatic Gain Control,
Address 0x2C [7:0] section.
Table 67. PW_UPD Function
PW_UPD Description
0 Update gain once per video line.
1 (default) Update gain once per field.
Chroma Gain
CAGC[1:0] Chroma Automatic Gain Control,
Address 0x2C [1:0]
The two bits of Color Automatic Gain Control mode select
the basic mode of operation for automatic gain control in the
chroma path.
Table 68. CAGC Function
CAGC[1:0] Description
00 Manual fixed gain (use CMG[11:0]).
01 Use luma gain for chroma.
10 (default) Automatic gain (based on color burst).
11 Freeze chroma gain.
CAGT[1:0] Chroma Automatic Gain Timing,
Address 0x2D [7:6]
The Chroma Automatic Gain Timing register allows the user
to influence the tracking speed of the chroma automatic gain
control. This register has an effect only if the CAGC[1:0]
register is set to 10 (automatic gain).
Name Betacam (mV) Betacam Variant (mV) SMPTE (mV) MII (mV)
Y Range 0 to 714 (incl. 7.5% pedestal) 0 to 714 0 to 700 0 to 700 (incl. 7.5% pedestal)
Pb and Pr Range –467 to +467 –505 to +505 –350 to +350 –324 to +324
Sync Depth 286 286 300 300
Rev. B | Page 33 of 104
ADV7181
CG[11:0] Chroma Gain, Address 0x2D [3:0];
Address 0x2E [7:0] CMG[11:0] Chroma Manual Gain,
Address 0x2D [3:0]; Address 0x2E [7:0]
Chroma gain [11:0] is a dual-function register:
•
If written to, a desired manual chroma gain can be
programmed. This gain becomes active if the CAGC[1:0]
mode is switched to manual fixed gain.
Refer to Equation 2 for calculating a desired gain.
•
•
If read back, this register returns the current gain value.
Depending on the setting in the CAGC[1:0] bits, this is one
of the following values:
o Chroma manual gain value (CAGC[1:0] set to chroma
manual gain mode).
o Chroma automatic gain value (CAGC[1:0] set to any
of the automatic modes).
Table 71. CG/CMG Function
CG[11:0]/CMG[11:0] Read/Write Description
CMG[11:0] Write
CG[11:0] Read Currently active gain.
_=
()
GainChroma
1024
Example
Freezing the automatic gain loop and reading back the
CG[11:0] register results in a value of 0x47A.
Convert the read back value to decimal:
1.
0x47A = 1146d
2.
Apply Equation 2 to convert the readback value:
1146/1024 = 1.12
Manual gain for chroma
path.
40950
≤<=CG
(2)
4...0
CKE Color Kill Enable, Address 0x2B [6]
The Color Kill Enable bit allows the optional color kill function
to be switched on or off.
For QAM-based video standards (PAL and NTSC) as well as
FM-based systems (SECAM), the threshold for the color kill
decision is selectable via the CKILLTHR[2:0] bits.
If color kill is enabled, and if the color carrier of the incoming
video signal is less than the threshold for 128 consecutive video
lines, color processing is switched off (black and white output).
To switch the color processing back on, another 128 consecutive
lines with a color burst greater than the threshold are required.
The color kill option only works for input signals with a modulated chroma part. For component input (YPrPb), there is no
color kill.
Table 72. CKE Function
CKE Description
0 Color kill disabled.
1 (default) Color kill enabled.
CKILLTHR[2:0] Color Kill Threshold, Address 0x3D [6:4]
The CKILLTHR[2:0] bits allow the user to select a threshold
for the color kill function. The threshold only applies to QAMbased (NTSC and PAL) or FM modulated (SECAM) video
standards.
To enable the color kill function, the CKE bit must be set. For
settings 000, 001, 010, and 011, chroma demodulation inside
the ADV7181 may not work satisfactorily for poor input video
signals.
Table 73. CKILLTHR Function
CKILLTHR[2:0]SECAM NTSC, PAL
000 No color kill Kill at < 0.5%
001 Kill at < 5% Kill at < 1.5%
010 Kill at < 7% Kill at < 2.5%
011 Kill at < 8% Kill at < 4.0%
100 (default) Kill at < 9.5% Kill at < 8.5%
101 Kill at < 15% Kill at < 16.0%
110 Kill at < 32% Kill at < 32.0%
111
Reserved for ADI internal use only. Do not
select.
Description
Rev. B | Page 34 of 104
ADV7181
CHROMA TRANSIENT IMPROVEMENT (CTI)
The signal bandwidth allocated for chroma is typically much
smaller than that of luminance. In the past, this was a valid way
to fit a color video signal into a given overall bandwidth because
the human eye is less sensitive to chrominance than to
luminance.
The uneven bandwidth, however, can lead to some visual
artifact when it comes to sharp color transitions. At the border
of two bars of color, both components (luma and chroma)
change at the same time (see Figure 17). Due to the higher
bandwidth, the signal transition of the luma component is
usually a lot sharper than that of the chroma component. The
color edge is not sharp but blurred, in the worst case, over
several pixels.
The CTI_AB_EN bit enables an alpha-blend function within
the CTI block. If set to 1, the alpha blender mixes the transient
improved chroma with the original signal. The sharpness of the
alpha blending can be configured via the CTI_AB[1:0] bits.
For the alpha blender to be active, the CTI block must be
enabled via the CTI_EN bit.
The chroma transient improvement block examines the input
video data. It detects transitions of chroma, and can be
programmed to “steepen” the chroma edges in an attempt to
artificially restore lost color bandwidth. The CTI block,
however, only operates on edges above a certain threshold to
ensure that noise is not emphasized. Care has been taken to
ensure that edge ringing and undesirable saturation or hue
distortion are avoided.
Chroma transient improvements are needed primarily for
signals that experienced severe chroma bandwidth limitations.
For those types of signals, it is strongly recommended to enable
the CTI block via CTI_EN.
The CTI_AB[1:0] controls the behavior of alpha-blend circuitry
that mixes the sharpened chroma signal with the original one. It
thereby controls the visual impact of CTI on the output data.
For CTI_AB[1:0] to become effective, the CTI block must be
enabled via the CTI_EN bit, and the alpha blender must be
switched on via CTI_AB_EN.
Sharp blending maximizes the effect of CTI on the picture, but
can also increase the visual impact of small amplitude, high
frequency chroma noise.
The CTI_C_TH[7:0] value is an unsigned, 8-bit number specifying how big the amplitude step in a chroma transition has to
be in order to be steepened by the CTI block. Programming a
small value into this register causes even smaller edges to be
steepened by the CTI block. Making CTI_C_TH[7:0] a large
value causes the block to improve large transitions only.
Table 77. CTI_C_TH Function
CTI_C_TH[7:0] Description
0x08 (default) Threshold for chroma edges prior to CTI.
Rev. B | Page 35 of 104
ADV7181
DIGITAL NOISE REDUCTION (DNR)
Digital noise reduction is based on the assumption that high
frequency signals with low amplitude are probably noise, and
that their removal therefore improves picture quality.
DNR_EN Digital Noise Reduction Enable, Address 0x4D [5]
The DNR_EN bit enables the DNR block or bypasses it.
Table 78. DNR_EN Function
DNR_EN Description
0 Bypass DNR (disable).
1 (default) Enable digital noise reduction on the luma data.
The DNR_TH[7:0] value is an unsigned 8-bit number used to
determine the maximum edge that is interpreted as noise and
therefore blanked from the luma data. Programming a large
value into DNR_TH[7:0] causes the DNR block to interpret
even large transients as noise and remove them. The effect on
the video data is therefore more visible.
Programming a small value causes only small transients to be
seen as noise and to be removed.
The recommended DNR_TH[7:0] setting for A/V inputs is
0x04, and the recommended DNR_TH[7:0] setting for tuner
inputs is 0x0A.
Table 79. DNR_TH Function
DNR_TH[7:0] Description
0x08 (default)
Threshold for maximum luma edges to be
interpreted as noise.
COMB FILTERS
The comb filters of the ADV7181 have been greatly improved to
automatically handle video of all types, standards, and levels of
quality. Two user registers are available to customize comb filter
operation.
Depending on whichever video standard has been detected (by
autodetection) or selected (by manual programming), the
NTSC or PAL configuration registers are used. In addition to
the bits listed in this section, there are some further ADI
internal controls; contact ADI for more information.
The NSFSEL[1:0] control selects how much of the overall signal
bandwidth is fed to the combs. A narrow split filter selection
gives better performance on diagonal lines, but leaves more dot
crawl in the final output image. The opposite is true for selecting
a wide bandwidth split filter.
The NSFSEL[1:0] control selects how much of the overall signal
bandwidth is fed to the combs. A wide split filter selection
eliminates dot crawl, but shows imperfections on diagonal lines.
The opposite is true for selecting a narrow bandwidth split filter.
0xx (default) Adaptive comb mode. Adaptive 5 lines (3 taps) luma comb.
100 Disable luma comb. Use low-pass/notch filter; see the Y Shaping Filter section.
101 Fixed luma comb (top lines of line memory). Fixed 3 lines (2 taps) luma comb.
110 Fixed luma comb (all lines of line memory). Fixed 5 lines (3 taps) luma comb.
111 Fixed luma comb (bottom lines of line memory). Fixed 3 lines (2 taps) luma comb.
Rev. B | Page 38 of 104
ADV7181
S
AV CODE INSERTION AND CONTROLS
This section describes the I2C-based controls that affect
Insertion of AV codes into the data stream
•
Data blanking during the vertical blank interval (VBI)
•
The range of data values permitted in the output data
•
stream
SD_DUP_AV Duplicate AV Codes, Address 0x03 [0]
Depending on the output interface width, it may be necessary to
duplicate the AV codes from the luma path into the chroma path.
In an 8-bit-wide output interface (Cb/Y/Cr/Y interleaved data),
the AV codes are defined as FF/00/00/AV, with AV being the
transmitted word that contains information about H/V/F.
•
The relative delay of luma vs. chroma signals
Some of the decoded VBI data is being inserted during the
horizontal blanking interval. See the Gemstar Data Recovery
section for more information.
BT656-4 ITU Standard BT-R.656-4 Enable, Address 0x04 [7]
The ITU has changed the position for toggling of the V bit
within the SAV EAV codes for NTSC between revisions 3 and 4.
The BT656-4 standard bit allows the user to select an output
mode that is compliant with either the previous or the new
standard. For further information, review the standard at
http://www.itu.int.
The standard change affects NTSC only and has no bearing on
PAL.
Table 88. BT656-4 Function
BT656-4 Description
0 (default)
BT656-3 Spec: V bit goes low at EAV of Lines 10
and 273.
1
BT656-4 Spec: V bit goes low at EAV of Lines 20
and 283.
In this output interface mode, the following assignment takes
place: Cb = FF, Y = 00, Cr = 00, and Y = AV.
In a 16-bit output interface where Y and Cr/Cb are delivered via
separate data buses, the AV code is over the whole 16 bits. The
SD_DUP_AV bit allows the user to double up the AV codes, so
the full sequence can be found on the Y bus as well as
(= duplicated) the Cr/Cb bus. See Figure 18.
Table 89. SD_DUP_AV Function
SD_DUP_AV Description
0
AV codes in single fashion (to suit 8-bit
interleaved data output).
1 AV codes duplicated (for 16-bit interfaces).
VBI_EN Vertical Blanking Interval Data Enable,
Address 0x03 [7]
The VBI enable bit allows data such as intercast and closed
caption data to be passed through the luma channel of the
decoder with only a minimal amount of filtering. All data for
Lines 1 to 21 is passed through and available at the output port.
The ADV7181 does not blank the luma data, and automatically
switches all filters along the luma data path into their widest
bandwidth. For active video, the filter settings for YSH and YPK
are restored.
SD_DUP_AV = 1SD_DUP_AV = 0
Y DATA BUS00AVYFF0000AVY
FFCr/Cb DATA BU
0000AVCbFF00Cb
AV CODE SECTIONAV CODE SECTION
Refer to the BL_C_VBI Blank Chroma during VBI section for
information on the chroma path.
Table 90. VBI_En Function
VBI_EN Description
0 (default) All video lines are filtered/scaled.
1 Only active video region is filtered/scaled.
Figure 18. AV Code Duplication Control
Rev. B | Page 39 of 104
Cb/Y/Cr/Y
INTERLEAVED
8-BIT INTERFACE16-BIT INTERFACE16-BIT INTERFACE
FF0000AV Cb
AV CODE SECTION
04820-018
ADV7181
BL_C_VBI Blank Chroma during VBI, Address 0x04 [2]
Setting BL_C_VBI high, the Cr and Cb values of all VBI lines
get blanked. This is done so any data that comes during VBI is
not decoded as color and output through Cr and Cb. As a result,
it should be possible to send VBI lines into the decoder, then
output them through an encoder again, undistorted. Without
this blanking, any wrongly decoded color is encoded by the
video encoder; therefore, the VBI lines are distorted.
Table 91. BL_C_VBI Function
BL_C_VBI Description
0 Decode and output color during VBI.
1 (default) Blank Cr and Cb values during VBI (no color, 0x80).
RANGE Range Selection, Address 0x04 [0]
AV codes (as per ITU-R BT-656, formerly known as CCIR-656)
consist of a fixed header made up of 0xFF and 0x00 values.
These two values are reserved and therefore are not to be used
for active video. Additionally, the ITU also specifies that the
nominal range for video should be restricted to values between
16 and 235 for luma and 16 to 240 for chroma.
The RANGE bit allows the user to limit the range of values
output by the ADV7181 to the recommended value range. In
any case, it is ensured that the reserved values of 255d (0xFF)
and 00d (0x00) are not presented on the output pins unless they
are part of an AV code header.
Enabling the AUTO_PDC_EN function activates a function
within the ADV7181 that automatically programs the LTA[1:0]
and CTA[2:0] to have the chroma and luma data match delays
for all modes of operation. If set, manual registers LTA[1:0] and
CTA[2:0] are not used by the ADV7181. If the automatic mode
is disabled (via setting the AUTO_PDC_EN bit to 0), the values
programmed into LTA[1:0] and CTA[2:0] registers take effect.
Table 93. AUTO_PDC_EN Function
AUTO_PDC_EN Description
0
1 (default)
Use LTA[1:0] and CTA[2:0] values for delaying
luma and chroma samples. Refer to the
LTA[1:0] Luma Timing Adjust, Address 0x27
[1:0] and CTA[2:0] Chroma Timing Adjust,
Address 0x27 [5:3] sections.
The ADV7181 automatically determines the
LTA and CTA values to have luma and chroma
aligned at the output.
LTA[1:0] Luma Timing Adjust, Address 0x27 [1:0]
The Luma Timing Adjust register allows the user to specify a
timing difference between chroma and luma samples.
There is a certain functionality overlap with the CTA[2:0]
register.
For manual programming, use the following defaults:
The Chroma Timing Adjust register allows the user to specify a
timing difference between chroma and luma samples. This can
be used to compensate for external filter group delay differences
in the luma vs. chroma path, and to allow a different number of
pipeline delays while processing the video down-stream. Review
this functionality together with the LTA[1:0] register.
The chroma can only be delayed/advanced in chroma pixel
steps. One chroma pixel step is equal to two luma pixels. The
programmable delay occurs after demodulation, where one can
no longer delay by luma pixel steps.
For manual programming, use the following defaults:
The HS Begin and HS End registers allow the user to freely
position the HS output (pin) within the video line. The values
in HSB[10:0] and HSE[10:0] are measured in pixel units from
the falling edge of HS. Using both values, the user can program
both the position and length of the HS output signal.
The position of this edge is controlled by placing a binary
number into HSB[10:0]. The number applied offsets the edge
with respect to an internal counter that is reset to 0 immediately
after EAV code FF,00,00,XY (see Figure 19). HSB is set to
00000000010b, which is 2 LLC1 clock cycles from count[0].
The HS Begin and HS End registers allow the user to freely
position the HS output (pin) within the video line. The values
in HSB[10:0] and HSE[10:0] are measured in pixel units from
the falling edge of HS. Using both values, the user can program
both the position and length of the HS output signal.
The HS pulse starts after the HSB[10:0] pixel after
falling edge of HS.
HS Begin Adjust
(HSB[10:0])
1
HS End Adjust
(HSE[10:0])1
The position of this edge is controlled by placing a binary
number into HSE[10:0]. The number applied offsets the edge
with respect to an internal counter that is reset to 0 immediately
after EAV code FF,00,00,XY (see Figure 19). HSE is set to
00000000000b, which is 0 LLC1 clock cycles from count[0].
Table 97. HSE Function
HSE[9:0] Description
000 (default)
HS pulse ends after HSE[10:0] pixel after falling
edge of HS.
Example
1. To shift the HS towards active video by 20 LLC1s, add
20 LLC1s to both HSB and HSE, that is, HSB[10:0] =
[00000010110], HSE[10:0] = [00000010100]
2.
To shift the HS away from active video by 20 LLC1s, add
1696 LLC1s to both HSB and HSE (for NTSC), that is,
HSB[10:0] = [11010100010], HSE[10:0] = [11010100000].
(1696 is derived from the NTSC total number of pixels =
1716)
To move 20 LLC1s away from active video is equal to subtracting 20 from 1716 and adding the result in binary to both
HSB[10:0] and HSE[10:0].
PHS Polarity HS, Address 0x37 [7]
The polarity of the HS pin can be inverted using the PHS bit.
Table 98. PHS Function
PHS Description
0 (default) HS active high.
1 HS active low.
HS to Active Video
(LLC1 Clock Cycles)
(C in Figure 19)1
Active Video
Samples/Line
(D in Figure 19)
Total LLC1
Clock Cycles
(E in Figure 19)
LLC1
PIXEL
BUS
CrYFF0000XY801080108010FF0000XYCbYCrYCbYCr
ACTIVE
VIDEO
HS
HSB[10:0]HSE[10:0]
D
E
4 LLC1
C
Figure 19. HS Timing
Rev. B | Page 41 of 104
SAVACTIVE VIDEOH BLANKEAV
E
D
04820-019
ADV7181
VS and FIELD Configuration
The following controls allow the user to configure the behavior
of the VS and FIELD output pins, as well as the generation of
embedded AV codes:
•
ADV encoder-compatible signals via NEWAVMODE PVS, PF
•
HVSTIM
•
VSBHO, VSBHE
•
HVSTIM Horizontal VS Timing, Address 0x31 [3]
The HVSTIM bit allows the user to select where the VS signal is
asserted within a line of video. Some interface circuitry may
require VS to go low while HS is low.
Table 101. HVSTIM Function
HVSTIM Description
0 (default) Start of line relative to HSE.
1 Start of line relative to HSB.
VSEHO, VSEHE
•
For NTSC control:
•
o NVBEGDELO, NVBEGDELE, NVBEGSIGN,
NVBEG[4:0]
o NVENDDELO, NVENDDELE, NVENDSIGN,
NVEND[4:0]
o NFTOGDELO, NFTOGDELE, NFTOGSIGN,
NFTOG[4:0]
For PAL control:
•
o PVBEGDELO, PVBEGDELE, PVBEGSIGN,
PVBEG[4:0]
o PVENDDELO, PVENDDELE, PVENDSIGN,
PVEND[4:0]
o PFTOGDELO, PFTOGDELE, PFTOGSIGN,
PFTOG[4:0]
NEWAVMODE New AV Mode, Address 0x31 [4]
Table 100. NEWAVMODE Function
NEWAVMODE Description
0
1 (default)
EAV/SAV codes generated to suit ADI
encoders. No adjustments possible.
Enable Manual Position of VSYNC, Field, and
AV codes using 0x34 to 0x37 and 0xE5 to 0xEA.
Default register settings are CCIR656
compliant; see Figure 20 for NTSC and
Figure 25 for PAL. For recommended manual
user settings, see Table 108 and Figure 21 for
NTSC; see Table 121 and Figure 26 for PAL.
VSBHO VS Begin Horizontal Position Odd, Address 0x32 [7]
The VSBHO and VSBHE bits select the position within a line at
which the VS pin (not the bit in the AV code) becomes active.
Some follow-on chips require the VS pin to change state only
when HS is high/low.
Table 102. VSBHO Function
VSBHO Description
0 (default)
1
VS pin goes high at the middle of a line of video
(odd field).
VS pin changes state at the start of a line (odd
field).
VSBHE VS Begin Horizontal Position Even, Address 0x32 [6]
The VSBHO and VSBHE bits select the position within a line at
which the VS pin (not the bit in the AV code) becomes active.
Some follow-on chips require the VS pin to change state only
when HS is high/low.
Table 103. VSBHE Function
VSBHE Description
0
1 (default)
VS pin goes high at the middle of a line of video
(even field).
VS pin changes state at the start of a line (even
field).
VSEHO VS End Horizontal Position Odd, Address 0x33 [7]
The VSEHO and VSEHE bits select the position within a line at
which the VS pin (not the bit in the AV code) becomes active.
Some follow-on chips require the VS pin to change state only
when HS is high/low.
Table 104. VSEHO Function
VSEHO Description
0
1 (default)
VS pin goes low (inactive) at the middle of a line
of video (odd field).
VS pin changes state at the start of a line (odd
field).
Rev. B | Page 42 of 104
ADV7181
VSEHE VS End Horizontal Position Even,
Address 0x33 [6]
The VSEHO and VSEHE bits select the position within a line at
which the VS pin (not the bit in the AV code) becomes active.
Some follow-on chips require the VS pin to change state only
when HS is high/low.
Table 105. VSEHE Function
VSEHE Description
0
(default)
VS pin goes low (inactive) at the middle of a line of
video (even field).
1 VS pin changes state at the start of a line (even field).
FIELD 1
OUTPUT
VIDEO
5251234567891011121319202122
PVS Polarity VS, Address 0x37 [5]
The polarity of the VS pin can be inverted using the PVS bit.
Table 106. PVS Function
PVS Description
0 (default) VS active high.
1 VS active low.
PF Polarity FIELD, Address 0x37 [3]
The polarity of the FIELD pin can be inverted using the PF bit.
Figure 21. NTSC Typical VSync/Field Positions Using Register Writes in Table 108
Table 108. Recommended User Settings for NTSC (See Figure 21)
Register Register Name Write
0x31 VSync Field Control 1 0x12
0x32 VSync Field Control 2 0x81
0x33 VSync Field Control 3 0x84
0x37 Polarity 0x29
0xE5 NTSV_V_Bit_Beg 0x0
0xE6 NTSC_V_Bit_End 0x3
0xE7 NTSC_F_Bit_Tog 0x85
Rev. B | Page 44 of 104
ADV7181
NVBEGSIGN NTSC VSync Begin Sign, Address 0xE5 [5]
Table 111. NVBEGSIGN Function
NVBEGSIGN Description
0
Delay start of VSync. Set for user manual
programming.
1 (default)
Advance start of VSync. Not recommended
for user programming.
For all NTSC/PAL VSync timing controls, both the V bit in the
AV code and the VSync on the VS pin are modified.
NFTOGDELO NTSC Field Toggle Delay on Odd Field,
Address 0xE7 [7]
Table 117. NFTOGDELO Function
NFTOGDELO Description
0 (default) No delay.
1
NFTOGDELE NTSC Field Toggle Delay on Even Field,
Address 0xE7 [6]
Table 118. NFTOGDELE Function
NFTOGDELE Description
0 No delay.
1 (default)
Delay VSync going low on an odd field by a
line relative to NVEND.
Delay VSync going low on an even field by a
line relative to NVEND
Delay end of VSync. Set for user manual
programming.
Advance end of VSync. Not recommended for
user programming.
Delay Field toggle/transition on an odd field
by a line relative to NFTOG.
Delay Field toggle/transition on an even field by
a line relative to NFTOG.
ADVANCE TOGGLE OF
FIELD BY NFTOG[4:0]
NOT VALID FOR USER
PROGRAMMING
NFTOGDELO
ADDITIONAL
DELAY BY
1 LINE
NFTOGSIGN
ODD FIELD?
10
FIELD
TOGGLE
Figure 24. NTSC FIELD Toggle
01
DELAY TOGGLE OF
FIELD BY NFTOG[4:0]
NOYES
NFTOGDELE
10
ADDITIONAL
DELAY BY
1 LINE
04820-024
NFTOGSIGN NTSC Field Toggle Sign, Address 0xE7 [5]
Table 119. NFTOGSIGN Function
NFTOGSIGN Description
0
Delay field transition. Set for user manual
programming.
1 (default)
Advance field transition. Not recommended
for user programming.
NFTOG[4:0] NTSC Field Toggle, Address 0xE7 [4:0]
Table 120. NFTOG Function
NFTOG Description
00011 (default) NTSC Field toggle position.
For all NTSC/PAL Field timing controls, both the F bit in the
AV code and the Field signal on the FIELD/DE pin are modified.
Table 121. Recommended User Settings for PAL
(see Figure 26)
Register Register Name Write
0x31 VSync Field Control 1 0x12
0x32 VSync Field Control 2 0x81
0x33 VSync Field Control 3 0x84
0x37 Polarity 0x29
0xE8 PAL_V_Bit_Beg 0x1
0xE9 PAL_V_Bit_End 0x4
0xEA PAL_F_Bit_Tog 0x6
Rev. B | Page 46 of 104
ADV7181
OUTPUT
VIDEO
OUTPUT
VIDEO
OUTPUT
VIDEO
FIELD 1
62262362462512345678910222324
H
V
PVBEG[4:0] = 0x5PVEND[4:0] = 0x4
F
PFTOG[4:0] = 0x3
FIELD 2
310311312313314315316317318319320321 322335336337
H
V
PVBEG[4:0] = 0x5PVEND[4:0] = 0x4
F
PFTOG[4:0] = 0x3
Figure 25. PAL Default (BT.656). The polarity of H, V, and F is embedded in the data.
FIELD 1
622623624
12345 678 91011 2324
625
04820-025
OUTPUT
OUTPUT
FIELD
OUTPUT
OUTPUT
VIDEO
OUTPUT
OUTPUT
FIELD
OUTPUT
HS
VS
PVBEG[4:0] = 0x1PVEND[4:0] = 0x4
PFTOG[4:0] = 0x6
FIELD 2
310311312
HS
VS
314315316317318319320321322323336337
313
PVBEG[4:0] = 0x1PVEND[4:0] = 0x4
PFTOG[4:0] = 0x6
04820-026
Figure 26. PAL Typical VSync/Field Positions Using Register Writes in Table 121
Rev. B | Page 47 of 104
ADV7181
VSYNC BY PVBEG[4:0]
NOT VALID FOR USER
PROGRAMMING
ADVANCE BEGIN OF
PVBEGSIGN
ODD FIELD?
01
DELAY BEGIN OF
VSYNC BY PVBEG[4:0]
NOYES
PVBEG[4:0] PAL VSync Begin, Address 0xE8 [4:0]
Table 125. PVBEG Function
PVBEG Description
00101 (default) PAL VSync begin position.
For all NTSC/PAL VSync timing controls, both the V bit in the
AV code and the VSync on the VS pin are modified.
PVENDSIGN
01
PVBEGDELO
10
ADDITIONAL
DELAY BY
1 LINE
VSBHO
10
ADVANCE BY
0.5 LINE
VSYNC BEGIN
PVBEGDELE
10
ADDITIONAL
DELAY BY
1 LINE
VSBHE
10
ADVANCE BY
0.5 LINE
Figure 27. PAL VSync Begin
PVBEGDELO PAL VSync Begin Delay on Odd Field,
Address 0xE8 [7]
Table 122. PVBEGDELO Function
PVBEGDELO Description
0 (default) No delay.
1
Delay VSync going high on an odd field by a line
relative to PVBEG.
04820-027
ADVANCE END OF
VSYNC BY PVEND[4:0]
NOT VALID FOR USER
PROGRAMMING
PVENDDELO
ADDITIONAL
DELAY BY
1 LINE
VSEHO
ADVANCE BY
0.5 LINE
ODD FIELD?
10
10
VSYNC END
Figure 28. PAL VSync End
DELAY END OF VSYNC
BY PVEND[4:0]
NOYES
PVENDDELE
10
ADDITIONAL
DELAY BY
1 LINE
VSEHE
10
ADVANCE BY
0.5 LINE
04820-028
PVBEGDELE PAL VSync Begin Delay on Even Field,
Address 0xE8 [6]
Table 123. PVBEGDELE Function
PVBEGDELE Description
0 No delay.
1 (default)
Delay VSync going high on an even field by a line
relative to PVBEG.
PVBEGSIGN PAL VSync Begin Sign, Address 0xE8 [5]
Table 124. PVBEGSIGN Function
PVBEGSIGN Description
0
Delay begin of VSync. Set for user manual
programming.
1 (default)
Advance begin of VSync. Not recommended for
user programming.
PVENDDELO PAL VSync End Delay on Odd Field,
Address 0xE9 [7]
Table 126. PVENDDELO Function
PVENDDELO Description
0 (default) No delay.
1
PVENDDELE PAL VSync End Delay on Even Field,
Address 0xE9 [6]
Table 127. PVENDDELE Function
PVENDDELE Description
0 (default) No delay.
1
Rev. B | Page 48 of 104
Delay VSync going low on an odd field by a
line relative to PVEND.
Delay VSync going low on an even field by a line
relative to PVEND.
ADV7181
PVENDSIGN PAL VSync End Sign, Address 0xE9 [5]
Table 128. PVENDSIGN Function
PVENDSIGN Description
0 (default)
Delay end of VSync. Set for user manual
programming.
1
Advance end of VSync. Not recommended
for user programming.
PVEND[4:0] PAL Vsync End, Address 0xE9,[4:0]
Table 129. PVEND Function
PVEND Description
10100 (default) PAL VSync end position.
For all NTSC/PAL VSync timing controls, both the V bit in the
AV code and the VSync on the VS pin are modified.
PFTOGDELO PAL Field Toggle Delay on Odd Field,
Address 0xEA [7]
Table 130. PFTOGDELO Function
PFTOGDELO Description
0 (default) No delay.
1
Delay F toggle/transition on an odd field by
a line relative to PFTOG.
PFTOGDELE PAL Field Toggle Delay on Even Field,
Address 0xEA [6]
Table 131. PFTOGDELE Function
PFTOGDELE Description
0 No delay.
1 (default)
Delay F toggle/transition on an even field by
a line relative to PFTOG.
PFTOGSIGN PAL Field Toggle Sign, Address 0xEA [5]
Table 132. PFTOGSIGN Function
PFTOGSIGN Description
0
Delay Field transition. Set for user manual
programming.
1 (default)
Advance Field transition. Not recommended
for user programming.
PFTOG PAL Field Toggle, Address 0xEA [4:0]
Table 133. PFTOG Function
PFTOG Description
00011 (default) PAL Field toggle position.
For all NTSC/PAL Field timing controls, the F bit in the AV
code and the Field signal on the FIELD/DE pin are modified.
ADVANCE TOGGLE OF
FIELD BY PTOG[4:0]
NOT VALID FOR USER
PROGRAMMING
PFTOGDELO
10
ADDITIONAL
DELAY BY
1 LINE
Figure 29. PAL F Toggle
SYNC PROCESSING
The ADV7181 has two additional sync processing blocks that
postprocess the raw synchronization information extracted
from the digitized input video. If desired, the blocks can be
disabled via the following two I
ENHSPLL Enable HSync Processor, Address 0x01 [6]
The HSYNC processor is designed to filter incoming HSyncs
that have been corrupted by noise, providing improved performance for video signals with stable time bases but poor SNR.
For CVBS PAL/NTSC, YC PAL/NTSC, enable the HSync
processor. For SECAM, disable the HSync processor. For YPrPb
signals, disable Hsync processor.
Table 134. ENHSPLL Function
ENHSPLL Description
0 Disable the HSync processor.
1 (default) Enable the HSync processor.
ENVSPROC Enable VSync Processor, Address 0x01 [3]
This block provides extra filtering of the detected VSyncs to
give improved vertical lock.
The following low data rate VBI signals can be decoded by the
ADV7181:
CCAPD Closed Caption Detected, Address 0x90 [1]
Logic 1 for this bit indicates that the data in the CCAP1 and
CCAP2 registers is valid.
Wide screen signaling (WSS)
•
Copy generation management systems (CGMS)
•
Closed captioning (CCAP)
•
EDTV
•
Gemstar 1×- and 2×-compatible data recovery
•
The presence of any of the above signals is detected and, if
applicable, a parity check is performed. The result of this testing
is contained in a confidence bit in the VBI Info[7:0] register.
Users are encouraged to first examine the VBI Info register
before reading the corresponding data registers. All VBI data
decode bits are read-only.
All VBI data registers are double-buffered with the field signals.
This means that data is extracted from the video lines and
2
appears in the appropriate I
C registers with the next field
transition. They are then static until the next field.
The user should start an I
2
C read sequence with VS by first
examining the VBI Info register. Then, depending on the data
detected, the appropriate data registers should be read.
The data registers are filled with decoded VBI data even if their
corresponding detection bits are low; it is likely that bits within
the decoded data stream are wrong.
Notes
•The closed captioning data (CCAP) is available in the I
2
C
registers, and is also inserted into the output video data
stream during horizontal blanking.
2
•The Gemstar-compatible data is not available in the I
C
registers, and is inserted into the data stream only during
horizontal blanking.
Logic 1 for this bit indicates that the data in the WSS1 and
WSS2 registers is valid.
The WSSD bit goes high if the rising edge of the start bit is
detected within a time window, and if the polarity of the parity
bit matches the data transmitted.
Table 136. WSSD Function
WSSD Description
0 No WSS detected. Confidence in decoded data is low.
1 WSS detected. Confidence in decoded data is high.
The CCAPD bit goes high if the rising edge of the start bit is
detected within a time window, and if the polarity of the parity
bit matches the data transmitted.
Table 137. CCAPD Function
CCAPD Description
0
1
No CCAP signals detected. Confidence in
decoded data is low.
CCAP sequence detected. Confidence in
decoded data is high.
EDTVD EDTV Sequence Detected, Address 0x90 [2]
Logic 1 for this bit indicates that the data in the EDTV1, 2, 3
registers is valid.
The EDTVD bit goes high if the rising edge of the start bit is
detected within a time window, and if the polarity of the parity
bit matches the data transmitted.
Table 138. EDTVD Function
EDTVD Description
0
1
No EDTV sequence detected. Confidence in
decoded data is low.
EDTV sequence detected. Confidence in
decoded data is high.
CGMSD CGMS-A Sequence Detected, Address 0x90 [3]
Logic 1 for this bit indicates that the data in the CGMS1, 2, 3
registers is valid. The CGMSD bit goes high if a valid CRC
checksum has been calculated from a received CGMS packet.
Table 139. CGMSD Function
CGMSD Description
0
1 CGMS sequence decoded, confidence high.
No CGMS transmission detected, confidence
low.
CRC_ENABLE CRC CGMS-A Sequence, Address 0xB2 [2]
For certain video sources, the CRC data bits may have an
invalid format. In such circumstances, the CRC checksum
validation procedure can be disabled. The CGMSD bit goes
high if the rising edge of the start bit is detected within a time
window.
Table 140. CRC_ENABLE Function
CRC_ENABLE Description
0
1 (default)
No CRC check performed. The CGMSD bit goes
high if the rising edge of the start bit is detected
within a time window.
Use CRC checksum to validate the CGMS-A
sequence. The CGMSD bit goes high for a valid
checksum. ADI recommended setting.
Figure 30 shows the bit correspondence between the analog
video waveform and the WSS1/WSS2 registers. WSS2[7:6] are
undetermined and should be masked out by software.
Figure 31 shows the bit correspondence between the analog
video waveform and the EDTV1/EDTV2/EDTV3 registers.
EDTV3[7:6] are undetermined and should be masked out by
software. EDTV3[5] is reserved for future use and, for now,
contains a 0. The three LSBs of the EDTV waveform are
currently not supported.
WSS2[5:0]WSS1[7:0]
0 1 2 3 4 5 6 7 0 1 2 3 4 5
CODE
38.4µs
42.5µs
ACTIVE
VIDEO
11.0µs
RUN-IN
SEQUENCE
START
Figure 30. WSS Data Extraction
Table 141. WSS Access Information
Signal Name Register Location Address Register Default Value
WSS1 [7:0] WSS 1 [7:0] 145d 0x91 Readback Only
WSS2 [5:0] WSS 2 [5:0] 146d 0x92 Readback Only
04820-030
EDTV1[7:0]EDTV2[7:0]EDTV3[5:0]
01
2
NOT SUPPORTED
3456701234567012345
Figure 31. EDTV Data Extraction
Table 142. EDTV Access Information
Signal Name Register Location Address Register Default Value
EDTV1[7:0] EDTV 1 [7:0] 147d 0x93 Readback Only
EDTV2[7:0] EDTV 2 [7:0] 148d 0x94 Readback Only
EDTV3[7:0] EDTV 3 [7:0] 149d 0x95 Readback Only
Figure 32 shows the bit correspondence between the analog
video waveform and the CGMS1/CGMS2/CGMS3 registers.
CGMS3[7:4] are undetermined and should be masked out by
software.
Figure 33 shows the bit correspondence between the analog
video waveform and the CCAP1/CCAP2 registers.
Notes
•CCAP1[7] contains the parity bit from the first word.
CCAP2[7] contains the parity bit from the second word.
•
Refer to the GDECAD Gemstar Decode Ancillary Data
Format, Address 0x4C [0] section.
+100 IRE
+70 IRE
0 IRE
–40 IRE
11.2µs
2.235µs
012 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3
±
20ns
CGMS2[7:0]CGMS3[3:0]CGMS1[7:0]REF
49.1µs±0.5µs
CRC SEQUENCE
Figure 32. CGMS Data Extraction
Table 143. CGMS Access Information
Signal Name Register Location Address Register Default Value
CGMS1[7:0] CGMS 1 [7:0] 150d 0x96 Readback Only
CGMS2[7:0] CGMS 2 [7:0] 151d 0x97 Readback Only
CGMS3[3:0] CGMS 3 [3:0] 152d 0x98 Readback Only
10.5±0.25µs12.91µs
7 CYCLES
50 IRE
40 IRE
REFERENCE COLOR BURST
FREQUENCY = F
(9 CYCLES)
= 3.579545MHz
SC
AMPLITUDE = 40 IRE
10.003µs
27.382µs
OF 0.5035MHz
(CLOCK RUN-IN)
CCAP1[7:0]
0
1
2 3 4 5 6 7 0 1 2 3 4 5 67
S
T
A
R
T
P
A
R
I
T
Y
33.764µs
CCAP2[7:0]
BYTE 1BYTE 0
P
A
R
I
T
Y
Figure 33. Closed Caption Data Extraction
Table 144. CCAP Access Information
Signal Name Register Location Address Register Default Value
CCAP1[7:0] CCAP 1 [7:0] 153d 0x99 Readback Only
CCAP2[7:0] CCAP 2 [7:0] 154d 0x9A Readback Only
04820-032
04820-033
Rev. B | Page 52 of 104
ADV7181
Letterbox Detection
Incoming video signals may conform to different aspect ratios
(16:9 wide screen of 4:3 standard). For certain transmissions in
the wide screen format, a digital sequence (WSS) is transmitted
with the video signal. If a WSS sequence is provided, the aspect
ratio of the video can be derived from the digitally decoded bits
WSS contains.
In the absence of a WSS sequence, letterbox detection can be
used to find wide screen signals. The detection algorithm examines the active video content of lines at the start and end of a
field. The detection of black lines can indicate that the
currently shown picture is in wide screen format.
The active video content (luminance magnitude) over a line of
video is summed together. At the end of a line, this accumulated
value is compared with a threshold, and a decision is made as to
whether or not a particular line is black. The threshold value
needed may depend on the type of input signal; some control is
provided via LB_TH[4:0].
Detection at the Start of a Field
The ADV7181 expects a section of at least six consecutive black
lines of video at the top of a field. Once those lines have been
detected, Register LB_LCT[7:0] reports back the number of
black lines that were actually found. By default, the ADV7181
starts looking for those black lines in sync with the beginning of
active video, for example, straight after the last VBI video line.
LB_SL[3:0] allows the user to set the start of letterbox detection
from the beginning of a frame on a line-by-line basis. The
detection window closes in the middle of the field.
Detection at the End of a Field
The ADV7181 expects at least six continuous lines of black
video at the bottom of a field before reporting back the number
of lines actually found via the LB_LCB[7:0] value. The activity
window for letterbox detection (end of field) starts in the middle of an active field. Its end is programmable via LB_EL[3:0].
Detection at the Midrange
Some transmissions of wide screen video include subtitles
within the lower black box. If the ADV7181 finds at least two
black lines followed by some more nonblack video, for example,
the subtitle, and finally followed by the remainder of the bottom
black block, it reports back a midcount via LB_LCM[7:0].
When no subtitles are found, LB_LCM[7:0] reports the same
number as LB_LCB[7:0].
Notes
to come to a conclusion about the presence of letterbox
type video in software.
LB_LCT[7:0] Letterbox Line Count Top, Address 0x9B [7:0];
LB_LCM[7:0] Letterbox Line Count Mid, Address 0x9C [7:0];
LB_LCB[7:0] Letterbox Line Count Bottom,
Address 0x9D [7:0]
Table 145. LB_LCx Access Information
Signal Name Address Register Default Value
LB_LCT[7:0] 0x9B Readback only
LB_LCM[7:0] 0x9C Readback only
LB_LCB[7:0] 0x9D Readback only
Letterbox detection is aligned with active
video. Window starts after the EDTV VBI data
line. For example, 0100 = 23/286 (NTSC).
LB_EL[3:0] Letterbox End Line, Address 0xDD [3:0]
Table 148. LB_EL Function
LB_EL[3:0] Description
1101 (default)
0001,0010 For example, 1100 = 261/524 (NTSC).
Letterbox detection ends with the last active
line of video on a field. For example, 1101 =
262/ 525 (NTSC).
Gemstar Data Recovery
The Gemstar-compatible data recovery block (GSCD) supports
1× and 2× data transmissions. In addition, it can also serve as a
closed caption decoder. Gemstar-compatible data transmissions
can only occur in NTSC. Closed caption data can be decoded in
both PAL and NTSC.
The block is configured via I
GDECEL[15:0] allow data recovery on selected video lines
•
2
C in the following way:
on even fields to be enabled and disabled.
•There is a 2-field delay in the reporting of any line count
parameters.
There is no “letterbox detected” bit. The user is asked to
•
read the LB_LCT[7:0] and LB_LCB[7:0] register values and
•
GDECOL[15:0] enable the data recovery on selected lines
Rev. B | Page 53 of 104
for odd fields.
ADV7181
•GDECAD configures the way in which data is embedded
in the video data stream. The recovered data is not available through I
blanking period of an ITU-R. BT656-compatible data
stream. The data format is intended to comply with the
recommendation by the International Telecommunications
Union, ITU-R BT.1364. See Figure 34. For more information, see the ITU website at www.itu.ch.
The format of the data packet depends on the following criteria:
Transmission is 1× or 2×.
•
Data is output in 8-bit or 4-bit format (see the description
•
of the GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C [0] bit).
•
Data is closed caption (CCAP) or Gemstar-compatible.
Data packets are output if the corresponding enable bit is set
(see the GDECEL and GDECOL descriptions) and if the
decoder detects the presence of data. This means that for video
lines where no data has been decoded, no data packet is output
even if the corresponding line enable bit is set.
2
C, but is inserted into the horizontal
Entries within the packet are as follows:
•
Fixed preamble sequence of 0x00, 0xFF, 0xFF. Data identification word (DID). The value for the DID
•
marking a Gemstar or CCAP data packet is 0x140
(10-bit value).
•
Secondary data identification word (SDID), which contains
information about the video line from which data was
retrieved, whether the Gemstar transmission was of 1× or
2× format, and whether it was retrieved from an even or
odd field.
•
Data count byte, giving the number of user data-words that
follow.
Us er data section.
•
Optional padding to ensure that the length of the user
•
data-word section of a packet is a multiple of four bytes.
(Requirement as set in ITU-R BT.1364.)
•Checksum byte.
Each data packet starts immediately after the EAV code of the
preceding line. See Figure 34 and Table 149, which show the
overall structure of the data packet.
DATA IDENTIFICATION
00FFFFDIDSDID
PREAMBLE FOR ANCILLARY DATA
SECONDARY DATA IDENTIFICATION
DATA
COUNT
Figure 34. Gemstar and CCAP Embedded Data Packet (Generic)
USER DATA (4 OR 8 WORDS)
Table 149 lists the values within a generic data packet that is
output by the ADV7181 in 8-bit format.
In 8-bit systems,
Bits D1 and D0 in the data packets are disregarded.
User Data-Words
(Including Padding) Padding Bytes DC[1:0]
Notes
•DID. The data identification value is 0x140 (10-bit value).
Care has been taken that in 8-bit systems, the 2 LSBs do
not carry vital information.
EP and !EP. The EP bit is set to ensure even parity on the
•
data-word D[8:0]. Even parity means there is always an
even number of 1s within the D[8:0] bit arrangement. This
includes the EP bit. !EP describes the logic inverse of EP
and is output on D[9]. The !EP is output to ensure that the
reserved codes of 00 and FF cannot happen.
EF. Even field identifier. EF = 1 indicates that the data was
•
recovered from a video line on an even field.
2X. This bit indicates whether the data sliced was in
•
Gemstar 1× or 2× format. A high indicates 2× format.
•
line[3:0]. This entry provides a code that is unique for each
of the possible 16 source lines of video from which
Gemstar data may have been retrieved. Refer to Table 162
and Table 163.
•
DC[1:0]. Data count value. The number of user data-words
in the packet divided by 4. The number of user data-words
(UDW) in any packet must be an integral number of 4.
Padding is required at the end, if necessary. (Requirement
as set in ITU-R BT.1364.) Refer to Table 150.
•
The 2X bit determines whether the raw information
retrieved from the video line was 2 or 4 bytes. The state of
the GDECAD bit affects whether the bytes are transmitted
straight (that is, two bytes transmitted as two bytes) or
whether they are split into nibbles (that is, two bytes
transmitted as four half bytes). Padding bytes are then
added where necessary.
CS[8:2]. The checksum is provided to determine the
•
integrity of the ancillary data packet. It is calculated by
summing up D[8:2] of DID, SDID, the Data Count byte,
and all UDWs, and ignoring any overflow during the
summation. Since all data bytes that are used to calculate
the checksum have their 2 LSBs set to 0, the CS[1:0] bits
are also always 0.
!CS[8] describes the logic inversion of CS[8]. The value
!CS[8] is included in the checksum entry of the data packet
to ensure that the reserved values of 0x00 and 0xFF do not
occur.
Table 151 to Table 154 outline the possible data packages.
Gemstar 2× Format, Half-Byte Output Mode
Half-byte output mode is selected by setting CDECAD = 0;
full-byte output mode is selected by setting CDECAD = 1.
See the GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C [0] section.
Gemstar 1× Format
Half-byte output mode is selected by setting CDECAD = 0;
full-byte output mode is selected by setting CDECAD = 1.
See the GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C [0] section.
Half-byte output mode is selected by setting CDECAD = 0;
the full-byte mode is enabled by CDECAD = 1. Refer to the
GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C [0] section. The data packet formats are
shown in Table 155 and Table 156.
Notes
•NTSC closed caption data is sliced on line 21d on even and
odd fields. The corresponding enable bit has to be set high.
See the GDECEL[15:0] Gemstar Decoding Even Lines,
Address 0x48 [7:0]; Address 0x49 [7:0] and GDECOL[15:0]
Gemstar Decoding Odd Lines, Address 0x4A [7:0];
Address 0x4B [7:0] sections.
Rev. B | Page 57 of 104
ADV7181
PAL CCAP Data
Half-Byte output mode is selected by setting CDECAD = 0,
full-byte output mode is selected by setting CDECAD = 1.
See the GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C [0] section. Table 157 and Table 158 list the
bytes of the data packet.
The 16 bits of the GDECEL[15:0] are interpreted as a collection
of 16 individual line decode enable signals. Each bit refers to a
line of video in an even field. Setting the bit enables the decoder
block trying to find Gemstar- or closed caption-compatible data
on that particular line. Setting the bit to 0 prevents the decoder
from trying to retrieve data. See Table 162 and Table 163.
GDECAD Gemstar Decode Ancillary Data Format,
Address 0x4C [0]
The decoded data from Gemstar-compatible transmissions or
closed caption is inserted into the horizontal blanking period of
the respective line of video. There is a potential problem if the
retrieved data bytes have the value 0x00 or 0xFF. In an ITU-R
BT.656-compatible data stream, those values are reserved and
used only to form a fixed preamble.
Notes
•To retrieve closed caption data services on NTSC
(Line 284), GDECEL[11] must be set.
To retrieve closed caption data services on PAL
•
(Line 335), GDECEL[14] must be set.
Table 159. GDECEL Function
GDECEL[15:0] Description
0x0000 (default)
Do not attempt to decode Gemstarcompatible data or CCAP on any line (even
field).
Table 163. PAL Line Enable Bits and Corresponding
Line Numbering
Line Number
line[3:0]
12 8 GDECOL[0] Not valid
13 9 GDECOL[1] Not valid
14 10 GDECOL[2] Not valid
15 11 GDECOL[3] Not valid
0 12 GDECOL[4] Not valid
1 13 GDECOL[5] Not valid
2 14 GDECOL[6] Not valid
3 15 GDECOL[7] Not valid
4 16 GDECOL[8] Not valid
5 17 GDECOL[9] Not valid
6 18 GDECOL[10] Not valid
7 19 GDECOL[11] Not valid
8 20 GDECOL[12] Not valid
9 21 GDECOL[13] Not valid
10 22 GDECOL[14] Closed caption
11 23 GDECOL[15] Not valid
12 321 (8) GDECEL[0] Not valid
13 322 (9) GDECEL[1] Not valid
14 323 (10) GDECEL[2] Not valid
15 324 (11) GDECEL[3] Not valid
0 325 (12) GDECEL[4] Not valid
1 326 (13) GDECEL[5] Not valid
2 327 (14) GDECEL[6] Not valid
3 328 (15) GDECEL[7] Not valid
4 329 (16) GDECEL[8] Not valid
5 330 (17) GDECEL[9] Not valid
6 331 (18) GDECEL[10] Not valid
7 332 (19) GDECEL[11] Not valid
8 333 (20) GDECEL[12] Not valid
9 334 (21) GDECEL[13] Not valid
10 335 (22) GDECEL[14] Closed caption
11 336 (23) GDECEL[15] Not valid
(ITU-R BT.470) Enable Bit Comment
Rev. B | Page 60 of 104
ADV7181
PIXEL PORT CONFIGURATION
The ADV7181 has a very flexible pixel port that can be configured in a variety of formats to accommodate downstream ICs.
Table 166 and Table 167 summarize the various functions that
the ADV7181’s pins can have in different modes of operation.
The ordering of components, for example, Cr vs. Cb, CHA/B/C,
can be changed. Refer to the SWPC Swap Pixel Cr/Cb, Address
0x27 [7] section. Table 166 indicates the default positions for
the Cr/Cb components.
OF_SEL[3:0] Output Format Selection, Address 0x03 [5:2]
There are several modes in which the ADV7181 pixel port
can be configured. These modes are under the control of
OF_SEL[3:0]. See Table 167 for details.
The default LLC frequency output on the LLC1 pin is approximately 27 MHz. For modes that operate with a nominal data
rate of 13.5 MHz (0001, 0010), the clock frequency on the LLC1
pin stays at the higher rate of 27 MHz. For information on
outputting the nominal 13.5 MHz clock on the LLC1 pin, see
the LLC1 Output Selection, LLC_PAD_SEL[2:0],
Address 0x8F [6:4] section.
The following I2C write allows the user to select between the
LLC1 (nominally at 27 MHz) and LLC2 (nominally at 13.5 MHz).
The LLC2 signal is useful for LLC2-compatible wide bus
(16-bit) output modes. See the OF_SEL[3:0] Output Format
Selection, Address 0x03 [5:2] section for additional
information. The LLC2 signal and data on the data bus are
synchronized. By default, the rising edge of LLC1/LLC2 is
aligned with the Y data; the falling edge occurs when the data
bus holds C data. The polarity of the clock, and therefore the
Y/C assignments to the clock edges, can be altered by using the
Polarity LLC pin.
Table 165. LLC_PAD_SEL Function
LLC_PAD_SEL[2:0] Description
000 (default) Output nominal 27 MHz LLC on LLC1 pin.
101 Output nominal 13.5 MHz LLC on LLC1 pin.
Table 166. P15–P0 Output/Input Pin Mapping
Data Port Pins P[15:0]
Processor, Format, and Mode 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Video Out, 8-Bit, 4:2:2 YCrCb[7:0]OUT
Video Out, 16-Bit, 4:2:2 Y[7:0]OUT CrCb[7:0] OUT
Table 167. Standard Definition Pixel Port Modes
P[15: 0]
OF_SEL[3:0]FormatP[15:8] P[7: 0]
0010 16-Bit @ LLC2 4:2:2 Y[7:0] CrCb[7:0]
0011 (default)8-Bit @ LLC1 4:2:2 YCrCb[7:0] Three-State
0110-1111 Reserved. Reserved. Do not use.
Rev. B | Page 61 of 104
ADV7181
S
S
MPU PORT DESCRIPTION
The ADV7181 supports a 2-wire (I2C-compatible) serial interface. Two inputs, serial data SDA and serial clock SCLK, carry
information between the ADV7181 and the system I
controller. Each slave device is recognized by a unique address.
The ADV7181’s I
2
C port allows the user to set up and configure
the decoder and to read back captured VBI data. The ADV7181
has four possible slave addresses for both read and write
operations, depending on the logic level on the ALSB pin. These
four unique addresses are shown in Table 168. The ADV7181’s
ALSB pin controls Bit 1 of the slave address. By altering the
ALSB, it is possible to control two ADV7181s in an application
without having a conflict with the same slave address. The LSB
(Bit 0) sets either a read or write operation. Logic 1 corresponds
to a read operation; Logic 0 corresponds to a write operation.
Table 168. I2C Address for ADV7181
ALSB R/W Slave Address
0 0 0x40
0 1 0x41
1 0 0x42
1 1 0x43
To control the device on the bus, a specific protocol must be
followed. First, the master initiates a data transfer by establishing
a start condition, which is defined by a high-to-low transition
on SDA while SCLK remains high. This indicates that an
address/data stream follows. All peripherals respond to the start
condition and shift the next eight bits (7-bit address + R/W bit).
The bits are transferred from MSB down to LSB. The peripheral
that recognizes the transmitted address responds by pulling the
data line low during the ninth clock pulse; this is known as an
acknowledge bit. All other devices withdraw from the bus at
this point and maintain an idle condition. The idle condition is
where the device monitors the SDA and SCLK lines, waiting for
the start condition and the correct transmitted address. The
R/W bit determines the direction of the data. Logic 0 on the
2
C master
LSB of the first byte means that the master writes information
to the peripheral. Logic 1 on the LSB of the first byte means that
the master reads information from the peripheral.
The ADV7181 acts as a standard slave device on the bus. The
data on the SDA pin is eight bits long, supporting the 7-bit
addresses plus the R/W bit. The ADV7181 has 196 subaddresses
to enable access to the internal registers. It therefore interprets
the first byte as the device address and the second byte as the
starting subaddress. The subaddresses auto-increment, allowing
data to be written to or read from the starting subaddress. A
data transfer is always terminated by a stop condition. The user
can also access any unique subaddress register on a one-by-one
basis without updating all the registers.
Stop and start conditions can be detected at any stage during
the data transfer. If these conditions are asserted out of
sequence with normal read and write operations, they cause an
immediate jump to the idle condition. During a given SCLK
high period, the user should issue only one start condition, one
stop condition, or a single stop condition followed by a single
start condition. If an invalid subaddress is issued by the user,
the ADV7181 does not issue an acknowledge and returns to the
idle condition.
If in auto-increment mode the user exceeds the highest
subaddress, the following action is taken:
In read mode, the highest subaddress register contents
1.
continue to be output until the master device issues a noacknowledge. This indicates the end of a read. A noacknowledge condition is when the SDA line is not pulled
low on the ninth pulse.
In write mode, the data for the invalid byte is not loaded
2.
into any subaddress register, a no acknowledge is issued by
the ADV7181, and the part returns to the idle condition.
SDATA
SCLOCK
WRITE
S
EQUENCE
READ
EQUENCE
SLAVE ADDR A(S) SUB ADDR A(S)DATAA(S)
S
SLAVE ADDRSLAVE ADDRA(S) SUB ADDR A(S) SA(S)DATAA(M)
S = START BIT
P = STOP BIT
SP
1–71–789891–789
START ADDRACKACKDATAACKSTOPSUBADDRESS
A(S) = ACKNOWLEDGE BY SLAVE
A(M) = ACKNOWLEDGE BY MASTER
R/W
Figure 35. Bus Data Transfer
LSB = 1LSB = 0
A(S) = NO-ACKNOWLEDGE BY SLAVE
A(M) = NO-ACKNOWLEDGE BY MASTER
Figure 36. Read and Write Sequence
Rev. B | Page 62 of 104
DATAA(S) P
04820-035
DATAA(M) P
04820-036
ADV7181
REGISTER ACCESSES
The MPU can write to or read from all of the ADV7181’s
registers, except those registers that are read-only or write-only.
The Subaddress register determines which register the next read
or write operation accesses. All communications with the part
through the bus start with an access to the Subaddress register.
Then a read/write operation is performed from/to the target
address, which increments to the next address until a stop
command on the bus is performed.
REGISTER PROGRAMMING
The following sections describe each register in terms of its
configuration. The Communications register is an 8-bit, writeonly register. After the part has been accessed over the bus and
a read/write operation is selected, the subaddress is set up. The
Subaddress register determines to/from which register the
operation takes place. Table 170 lists the various operations
under the control of the Subaddress register for the control
port.
Register Select (SR7-SR0)
These bits are set up to point to the required starting address.
I2C SEQUENCER
An I2C sequencer is used when a parameter exceeds eight bits,
and is therefore distributed over two or more I
example, HSB [11:0].
When such a parameter is changed using two or more I
operations, the parameter may hold an invalid value for the
time between the first I
2
C finishing and the last I2C being
completed. In other words, the top bits of the parameter may
already hold the new value while the remaining bits of the
parameter still hold the previous value.
2
To avoid this problem, the I
C sequencer holds the already
updated bits of the parameter in local memory; all bits of the
parameter are updated together once the last register write
operation has completed.
The correct operation of the I
2
C sequencer relies on the
following:
•
All I
2
C registers for the parameter in question must be
written to in order of ascending addresses, for example, for
HSB[10:0], write to Address 0x34 first, followed by 0x35.
No other I
•
2
C taking place between the two (or more) I2C
writes for the sequence, for example, for HSB[10:0], write
to Address 0x34 first, immediately followed by 0x35.
2
C registers, for
2
C write
Rev. B | Page 63 of 104
ADV7181
I2C CONTROL REGISTER MAP
Table 169. Control Port Register Map Details
Subaddress
Register Name Reset Value rw
Input Control 0000 0000 rw 0 00
Video Selection 1100 1000 rw 1 01
Reserved 0000 0100 rw 2 02
Output Control 0000 1100 rw 3 03
Extended Output Control 0101 0101 rw 4 04
Reserved 0000 0000 rw 5 05
Reserved 0000 0010 rw 6 06
Autodetect Enable 0111 1111 rw 7 07
Contrast 1000 0000 rw 8 08
Reserved 1000 0000 rw 9 09
Brightness 0000 0000 rw 10 0A
Hue 0000 0000 rw 11 0B
Default Value Y 0011 0110 rw 12 0C
Default Value C 0111 1100 rw 13 0D
ADI Control 0000 0101 rw 14 0E
Power Management 0000 0000 rw 15 0F
Status 1 xxxx xxxx r 16 10
Ident xxxx xxxx r 17 11
Status 2 xxxx xxxx r 18 12
Status 3 xxxx xxxx r 19 13
Analog Clamp Control 0001 0010 rw 20 14
Digital Clamp Control 1 0100 xxxx rw 21 15
Reserved xxxx xxxx rw 22 16
Shaping Filter Control 0000 0001 rw 23 17
Shaping Filter Control 2 1001 0011 rw 24 18
Comb Filter Control 1111 0001 rw 25 19
Reserved xxxx xxxx rw 26–38 1A–26
Pixel Delay Control 0101 1000 rw 39 27
Reserved xxxx xxxx rw 40 28–2A
Misc Gain Control 1110 0011 rw 43 2B
AGC Mode Control 1010 1110 rw 44 2C
Chroma Gain Control 1 1111 0100 rw 45 2D
Chroma Gain Control 2 0000 0000 rw 46 2E
Luma Gain Control 1 1111 xxxx rw 47 2F
Luma Gain Control 2 xxxx xxxx rw 48 30
VSync Field Control 1 0001 0010 rw 49 31
VSync Field Control 2 0100 0001 rw 50 32
VSync Field Control 3 1000 0100 51 33
HSync Position Control 1 0000 0000 rw 52 34
HSync Position Control 2 0000 0010 rw 53 35
HSync Position Control 3 0000 0000 rw 54 36
Polarity 0000 0001 rw 55 37
NTSC Comb Control 1000 0000 rw 56 38
PAL Comb Control 1100 0000 rw 57 39
ADC Control 0001 0000 rw 58 3A
Reserved xxxx xxxx rw 59–60 3B–3C
Manual Window Control 0100 0011 rw 61 3D
Reserved 0101 0000 rw 62–70 3E–47
Gemstar Ctrl 1 00000000 rw 72 48
Gemstar Ctrl 2 0000 0000 rw 73 49
Dec Hex
Register Name Reset Value rw
Gemstar Ctrl 3 0000 0000 rw 74 4A
Gemstar Ctrl 4 0000 0000 rw 75 4B
GemStar Ctrl 5 xxxx xxx0 rw 76 4C
CTI DNR Ctrl 1 1110 1111 rw 77 4D
CTI DNR Ctrl 2 0000 1000 rw 78 4E
Reserved xxxx xxxx rw 79 4F
CTI DNR Ctrl 4 0000 1000 rw 80 50
Lock Count 1010 0100 rw 81 51
Reserved xxxx xxxx rw 82–142 52–8E
Free Run Line Length 1 0000 0000 w 143 8F
Reserved 0000 0000 w 144 90
VBI Info xxxx xxxx r 144 90
WSS 1 xxxx xxxx r 145 91
WSS 2 xxxx xxxx r 146 92
EDTV 1 xxxx xxxx r 147 93
EDTV 2 xxxx xxxx r 148 94
EDTV 3 xxxx xxxx r 149 95
CGMS 1 xxxx xxxx r 150 96
CGMS 2 xxxx xxxx r 151 97
CGMS 3 xxxx xxxx r 152 98
CCAP 1 xxxx xxxx r 153 99
CCAP 2 xxxx xxxx r 154 9A
Letterbox 1 xxxx xxxx r 155 9B
Letterbox 2 xxxx xxxx r 156 9C
Letterbox 3 xxxx xxxx r 157 9D
Reserved xxxx xxxx rw 158-177 9E–B1
CRC Enable 0001 1100 w 178 B2
Reserved xxxx xxxx rw 179–194 B2–C2
ADC Switch 1 xxxx xxxx rw 195 C3
ADC Switch 2 0xxx xxxx rw 196 C4
Reserved xxxx xxxx rw 197–219 C5–DB
Letterbox Control 1 1010 1100 rw 220 DC
Letterbox Control 2 0100 1100 rw 221 DD
Reserved 0000 0000 rw 222 DE
Reserved 0000 0000 rw 223 DF
Reserved 0001 0100 rw 224 E0
SD Offset Cb 1000 0000 rw 225 E1
SD Offset Cr 1000 0000 rw 226 E2
SD Saturation Cb 1000 0000 rw 227 E3
SD Saturation Cr 1000 0000 rw 228 E4
NTSC V Bit Begin 0010 0101 rw 225 E5
NTSC V Bit End 0000 0100 rw 226 E6
NTSC F Bit Toggle 0110 0011 rw 227 E7
PAL V Bit Begin 0110 0101 rw 225 E8
PAL V Bit End 0001 0100 rw 226 E9
PAL F Bit Toggle 0110 0011 rw 227 EA
Subaddress
Dec Hex
Rev. B | Page 64 of 104
ADV7181
Table 170. Control Port Register Map Bit Details
Register Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Input Control VID_SEL.3 VID_SEL.2 VID_SEL.1 VID_SEL.0 INSEL.3 INSEL.2 INSEL.1 INSEL.0
Video Selection ENHSPLL BETACAM ENVSPROC
Reserved
Output Control VBI_EN TOD OF_SEL.3 OF_SEL.2 OF_SEL.1 OF_SEL.0 SD_DUP_AV
Extended Output
Control
Reserved
Reserved
Autodetect Enable AD_SEC525_EN AD_SECAM_EN AD_N443_EN AD_P60_EN AD_PALN_EN AD_PALM_EN AD_NTSC_EN AD_PAL_EN
Contrast CON.7 CON.6 CON.5 CON.4 CON.3 CON.2 CON.1 CON.0
Reserved
Brightness BRI.7 BRI.6 BRI.5 BRI.4 BRI.3 BRI.2 BRI.1 BRI.0
Hue HUE.7 HUE.6 HUE.5 HUE.4 HUE.3 HUE.2 HUE.1 HUE.0
Default Value Y DEF_Y.5 DEF_Y.4 DEF_Y.3 DEF_Y.2 DEF_Y.1 DEF_Y.0 DEF_VAL_AUTO_EN DEF_VAL_EN
Default Value C DEF_C.7 DEF_C.6 DEF_C.5 DEF_C.4 DEF_C.3 DEF_C.2 DEF_C.1 DEF_C.0
ADI Control TRI_LLC DR_STR_C.1 DR_STR_C.0 DR_STR_S.1 DR_STR_S.0
Power Management PWRDN PDBP
Status 1 COL_KILL AD_RESULT.2 AD_RESULT.1 AD_RESULT.0 FOLLOW_PW FSC_LOCK LOST_LOCK IN_LOCK
Ident IDENT.7 IDENT.6 IDENT.5 IDENT.4 IDENT.3 IDENT.2 IDENT.1 IDENT.0
Status 2 FSC NSTD LL NSTD MV AGC DET MV PS DET MVCS T3 MVCS DET
Status 3 PAL SW LOCK INTERLACE STD FLD LEN FREE_RUN_ACT INST_HLOC K
Analog Clamp
Control
Digital Clamp
Control 1
Reserved
Shaping Filter
Control
Shaping Filter
Control 2
Comb Filter Control NSFSEL.1 NSFSEL.0 PSFSEL.1 PSFSEL.0
Reserved
Pixel Delay Control SWPC AUTO_PDC_EN CTA.2 CTA.1 CTA.0 LTA.1 LTA.0
Reserved
Misc Gain Control CKE PW_UPD
AGC Mode Control LAGC.2 LAGC.1 LAGC.0 CAGC.1 CAGC.0
Chroma Gain
Control 1
Chroma Gain
Control 2
Luma Gain
Control 1
Luma Gain
Control 2
VSync Field
Control 1
VSync Field
Control 2
VSync Field
Control 3
HSync Position
Control 1
HSync Position
Control 2
HSync Position
Control 3
Polarity PHS PVS PF PCLK
NTSC Comb Control CTAPSN.1 CTAPSN.0 CCMN.2 CCMN.1 CCMN.0 YCMN.2 YCMN.1 YCMN.0
PAL Comb Control CTAPSP.1 CTAPSP.0 CCMP.2 CCMP.1 CCMP.0 YCMP.2 YCMP.1 YCMP.0
ADC Control PWRDN_AD C_0 PWRDN_AD C_1 PWRDN_ADC_2
Reserved
Manual Window
Control
Reserved
BT656-4 DR_STR.1 DR_STR.0 TIM_OE BL_C_VBI EN_SFL_PI RANGE
0 1 0 0 Not used
0 1 0 1 Not used
0 1 1 0 Not used
0 1 1 1 Not used
1 0 0 0 Not used
1 0 0 1 Not used
1 0 1 0 Not used
1 0 1 1 Not used
1 1 0 0 Not used
1 1 0 1 Not used
1 1 1 0 Not used
1 1 1 1 Not used See also
0 Output pins enabled
1 Drivers three-stated
0 All lines filtered and
1 Only active video
Register Setting Comments
interleaved data
output
(for 16-bit interfaces)
ITU-R BT.656
scaled
region filtered
TIM_OE
(
Table 174);
TRI_LLC
(
Table 176)
Rev. B | Page 68 of 104
ADV7181
Table 174. Register 0x04
Subaddress Register Bit Description
0x04 Extended
Output
Control
RANGE. Allows the user to select
the range of output values. Can
be BT656 compliant, or can fill the
whole accessible number range.
EN_SFL_PIN.
BL_C_VBI. Blank Chroma during
VBI. If set, enables data in the VBI
region to be passed through the
decoder undistorted.
TIM_OE. Timing signals output
enable.
DR_STR[1:0]. Drive strength of
output drivers can be increased or
decreased for EMC or crosstalk
reasons.
Reserved.
BT656-4. Allows the user to select
an output mode compatible with
ITU- R BT656-3/4.
x Color kill is active = 1
0x11 Info. Read-only
x x x x x x x x
0 0 Set to default
controlled by pin
disregarded)
See PDBP, 0x0F,
Bit 2
Executing reset
takes approx. 2 ms.
This bit is self
clearing.
read)
active = 1
Detected standard
Rev. B | Page 72 of 104
ADV7181
Table 178. Registers 0x12 and 0x13
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Register Setting Comments
0x12 Status Register 2.
Read-only.
0x13 Status Register 3.
Read-only.
STATUS_2[7:0]. Provides
information about the internal status
of the decoder.
STATUS_2[5:0]. x MV color striping
x MV color striping
x MV pseudosync
x MV AGC pulses
x Nonstandard line
x Fsc frequency
Reserved.
STATUS_3[7:0]. Provides
information about the internal status
of the decoder.
Table 179. Register 0x14
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Register Setting
0x14 Analog Clamp
Control
CCLEN. Current clamp enable allows the user to
switch off the current sources in the analog front.
Reserved.
Table 180. Register 0x15
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Register Setting
0x15 Digital Clamp
Control 1
Reserved. x x x x x Set to default
DCT[1:0]. Digital clamp timing determines the
time constant of the digital fine clamp circuitry.
Reserved.
detected
type
detected
detected
length
nonstandard
x x
x 1 = Horizontal
x x x 1 = Reserved bits No function
x 1 = Free Run
x 1 = Field length
x 1 = Swinging
Reserved.
0 I sources switched off.
Reserved.
0 0 Reserved. Set to default.
0 0 Slow (TC = 1 s)
0 1 Medium (TC = 0.5 s)
1 0 Fast (TC = 0.1 s)
1 1 TC dependent on video
0 Set to default
1 I sources enabled.
0 Reserved. Set to default.
lock achieved
mode active
standard
burst detected
0 0 1 0 Reserved. Set to default.
1 = Detected
0 = Type 2,
1 = Type 3
1 = Detected
1 = Detected
1 = Detected
1 = Detected
Unfiltered
Blue screen
output
Reliable
sequence
Rev. B | Page 73 of 104
ADV7181
Table 181. Register 0x17
Subaddress Register Bit Description
0x17 Shaping
Filter
Control
YSFM[4:0]. Selects Y
Shaping Filter mode
when in CVBS only
mode. Allows the user to
select a wide range of
low-pass and notch
filters.
If either auto mode is
selected, the decoder
selects the optimum Y
filter depending on the
CVBS video source
quality (good vs. bad).
CSFM[2:0]. C Shaping
Filter mode allows the
selection from a range of
low-pass chrominance
filters.
If either auto mode is
selected, the decoder
selects the optimum C
filter depending on the
CVBS video source
quality (good vs. bad).
Non-auto settings force
a C filter for all standards
and quality of CVBS
video.
quality sources or wideband filter with Comb for
good quality input.
quality sources or wideband
filter with comb for good
quality input.
Decoder selects
optimum Y shaping
filter depending on
CVBS quality.
If one of these modes is
selected, the decoder
does not change filter
modes depending on
video quality. A fixed
filter response (the one
selected) is used for
good and bad quality
video.
Automatically selects a
C filter based on video
standard and quality.
Selects a C filter for all
video standards and for
good and bad video.
Rev. B | Page 74 of 104
ADV7181
Table 182. Register 0x18 to 0x19
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Comments
0x18 Shaping
Filter
Control 2
0x19 Comb
Filter
Control
WYSFM[4:0] Wideband Y Shaping Filter mode allows
the user to select which Y shaping filter is used for the Y
component of Y/C, YPbPr, B/W input signals; it is also
used when a good quality input CVBS signal is
detected. For all other inputs, the Y shaping filter
chosen is controlled by YSFM[4:0].
WYSFMOVR. Enables the use of the automatic WYSFN
filter.
PSFSEL[1:0]. Controls the signal bandwidth that is fed
to the comb filters (PAL).
NSFSEL[1:0]. Controls the signal bandwidth that is fed
to the comb filters (NTSC).
Reserved. 0 0 1 1 Set to default
CKILLTHR[2:0].
0 0 0 Kill at 0.5%
0 0 1 Kill at 1.5%
0 1 0 Kill at 2.5%
0 1 1 Kill at 4%
1 0 0 Kill at 8.5%
1 0 1 Kill at 16%
1 1 0 Kill at 32%
1 1 1 Reserved
Reserved.
SFL_INV. Controls the
behavior of the PAL switch
bit.
Reserved.
GDECEL[15:0]. 16
individual enable bits that
select the lines of video
(even field Lines 10–25)
that the decoder checks
for Gemstar-compatible
data.
GDECEL[15:8]. See above.
GDECEL[7:0]. See above.
GDECOL[15:0]. 16
individual enable bits that
select the lines of video
(odd field lines 10–25) that
the decoder checks for
Gemstar-compatible data.
GDECOL[15:8]. See above.
GDECOL[7:0]. See above.
GDECAD. Controls the
manner in which decoded
Gemstar data is inserted
into the horizontal
blanking period.
Reserved.
0 Set to default
Reserved.
0 SFL-compatible with
0 Set to default
0 0 0 0 0 0 0 0
0x49 Gemstar
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0x4B Gemstar
0 0 0 0 0 0 0 0
0 Split data into half byte To avoid 00/FF
1 Output in straight 8-bit format
x x x x x x x Undefined
0 1 0 0 0 0 Set to default
ADV7190/ADV7191/ADV7194
encoders
1 SFL-compatible with
ADV717x/ADV7173x encoders
CKE = 1 enables the color kill function and
must be enabled for CKILLTHR[2:0] to take
effect.
LSB = Line 10
MSB = Line 25
Default = Do not
check for
Gemstarcompatible data
on any lines [10–
25] in even fields
LSB = Line 10
MSB = Line 25
Default = Do not
check for
Gemstarcompatible data
on any lines [10–
25] in odd fields
code
Rev. B | Page 83 of 104
ADV7181
Table 194. Registers 0x4D to 0x50
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Comments
0x4D CTI DNR
Control 1
Control 2
0x50 CTI DNR
Control 4
CTI_EN. CTI enable.
CTI_AB_EN. Enables the mixing of the
transient improved chroma with the
original signal.
CTI_AB[1:0]. Controls the behavior of the
alpha-blend circuitry.
DNR_EN. Enable or bypass the DNR block.
Reserved.
CTI_CTH[7:0]. Specifies how big the
amplitude step must be to be steepened
by the CTI block.
DNR_TH[7:0]. Specifies the maximum
edge that is interpreted as noise and is
therefore blanked.
0 Disable CTI
0 Disable CTI alpha blender
0 0 Sharpest mixing
0 1 Sharp mixing
1 0 Smooth
Reserved.
0 Bypass the DNR block
Reserved.
1 Set to default
0x4E CTI DNR
0 0 0 0 1 0 0 0
Set to 0x04 for A/V input; set to
0 0 0 0 1 0 0 0
1 Enable the DNR block
1 Set to default
1 1 Smoothest
0 Set to default
1 Enable CTI
1 Enable CTI alpha blender
0x0A for tuner input.
Rev. B | Page 84 of 104
ADV7181
Table 195. Register 0x51
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Comments Notes
0x51 Lock
Count
CIL[2:0]. Count-into-lock
determines the number of lines
the system must remain in lock
before showing a locked status.
COL[2:0]. Count-out-of-lock
determines the number of lines
the system must remain out-oflock before showing a lostlocked status.
SRLS. Select raw lock signal.
Selects the determination of
the lock status.
FSCLE. Fsc lock enable.
0 0 0 1 line of video
0 0 1 2 lines of video
0 1 0 5 lines of video
0 1 1 10 lines of video
1 0 0 100 lines of video
1 0 1 500 lines of video
1 1 0 1000 lines of video
1 1 1 100000 lines of video
0 0 0 1 line of video
0 0 1 2 lines of video
0 1 0 5 lines of video
0 1 1 10 lines of video
1 0 0 100 lines of video
1 0 1 500 lines of video
1 1 0 1000 lines of video
1 1 1 100000 lines of video
0 Over field with vertical
info
1 Line-to-line evaluation
FSCLE must be set to
0 Lock status set only by
horizontal lock
1 Lock status set by
horizontal lock and
subcarrier lock
0 in YPrPb mode if a
reliable LOST_LOCK
bit is set to 0.
Rev. B | Page 85 of 104
ADV7181
Table 196. Registers 0x8F and 0x90
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Comments Notes
0x8F Free Run
0x90 VBI Info
Line
Length 1
Read Mode
Details
LLC_PAD_SEL [2:0]. Enables
manual selection of clock for
LLC1 pin.
Reserved.
WSSD. Screen signaling
detected.
CCAPD. Closed caption data.
EDTVD. EDTV sequence.
CGMSD. CGMS sequence.
Reserved.
Reserved.
0 0 0 LLC1 (nominally
1 0 1 LLC2 (nominally
0 Set to default
0 No WSS detected
1 WSS detected
0 No CCAP signals
1 CCAP sequence
0 No EDTV sequence
1 EDTV sequence
0 No CGMS transition
1 CGMS sequence
x x x x
0 0 0 0 Set to default
27 MHz) selected out
on LLC1 pin
13.5 MHz) selected out
on LLC1 pin
detected
detected
detected
detected
detected
decoded
For 16-bit 4:2:2 out,
OF_SEL[3:0] = 0010
Ready-only status
bits
Rev. B | Page 86 of 104
ADV7181
Table 197. Registers 0x91 to 0x9D
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Comments Notes
0x91
x x x x x x x x
WSS2[7:6] are
x x x x x x x x
0x93
x x x x x x x x
0x94
x x x x x x x x
EDTV3[7:6] are
x x x x x x x x
0x96
x x x x x x x x
0x97
x x x x x x x x
CGMS3[7:4] are
x x x x x x x x
CCAP1[7] contains parity
x x x x x x x x
CCAP2[7] contains parity
x x x x x x x x
0x9B
x x x x x x x x
0x9C
x x x x x x x x
0x9D
x x x x x x x x
undetermined.
undetermined.
undetermined.
bit for Byte 0.
bit for Byte 0.
Reports the number of
black lines detected at
top of active video.
Reports the number of
black lines detected in
the bottom half of active
video if subtitles are
detected.
Reports the number of
black lines detected at
the bottom of active
video.
0x92
0x95
0x98
0x99
0x9A
WSS1[7:0]. Wide
screen signaling
data. Read-only.
WSS1[7:0]. Wide
screen signaling
data. Read-only.
EDTV1[7:0].
EDTV data. Readonly.
EDTV2[7:0].
EDTV data. Readonly.
EDTV3[7:0].
EDTV data. Readonly.
CGMS1[7:0].
CGMS data.
Read-only.
CGMS2[7:0].
CGMS data.
Read-only.
CGMS3[7:0].
CGMS data.
Read-only.
CCAP1[7:0].
Closed caption
data. Read-only.
CCAP2[7:0].
Closed caption
data. Read-only.
Letterbox 1.
Read-only.
Letterbox 2.
Read-only.
Letterbox 3.
Read-only.
WSS1[7:0]
WSS2[7:0]
EDTV1[7:0]
EDTV2[7:0]
EDTV3[7:0]
CGMS1[7:0]
CGMS2[7:0]
CGMS3[7:0]
CCAP1[7:0]
CCAP2[7:0]
LB_LCT[7:0]
LB_LCM[7:0]
LB_LCB[7:0]
Table 198. Register 0xB2
Bit
Subaddress Register Bit Description 7 6 5 4 3 2 1 0 Comments
0xB2 CRC Enable
Write
CRC_ENABLE. Enables CRC checksum
decoded from CGMS packet to validate
CGMSD.
Reserved.
Reserved.
0 Turn off CRC check.
0 0 0 1 1 Set as default.
1 CGMSD goes high with
EDTV3[5] is reserved for
future use.
This feature examines the
active video at the start and
at the end of each field. It
enables format detection
even if the video is not
accompanied by a CGMS or
WSS sequence.
ADI recommended programming sequence. This sequence must be followed exactly when
setting up the decoder.
Rev. B | Page 95 of 104
ADV7181
PCB LAYOUT RECOMMENDATIONS
The ADV7181 is a high precision, high speed mixed-signal
device. To achieve the maximum performance from the part, it
is important to have a well laid out PCB board. The following is
a guide for designing a board using the ADV7181.
ANALOG INTERFACE INPUTS
The inputs should receive care when being routed on the PCB.
Track lengths should be kept to a minimum, and 75 Ω trace
impedances should be used when possible. Trace impedances
other than 75 Ω also increase the chance of reflections.
POWER SUPPLY DECOUPLING
It is recommended to decouple each power supply pin with
0.1 µF and 10 nF capacitors. The fundamental idea is to have a
decoupling capacitor within about 0.5 cm of each power pin.
Also, avoid placing the capacitor on the opposite side of the PC
board from the ADV7181; doing so interposes resistive vias in
the path. The decoupling capacitors should be located between
the power plane and the power pin. Current should flow from
the power plane to the capacitor to the power pin. Do not make
the power connection between the capacitor and the power pin.
Placing a via underneath the 100 nF capacitor pads, down to the
power plane, is generally the best approach (see Figure 37).
It is also recommend to use a single ground plane for the entire
board. This ground plane should have a spacing gap between
the analog and digital sections of the PCB (see Figure 38).
ADV7181
ANALOG
SECTION
Figure 38. PCB Ground Layout
DIGITAL
SECTION
04820-037
Experience has repeatedly shown that the noise performance is
the same or better with a single ground plane. Using multiple
ground planes can be detrimental because each separate ground
plane is smaller, and long ground loops can result.
In some cases, using separate ground planes is unavoidable. For
those cases, it is recommended to at least place a single ground
plane under the ADV7181. The location of the split should be
under the ADV7181. For this case, it is even more important to
place components wisely because the current loops are much
longer (current takes the path of least resistance). An example
of a current loop: power plane to ADV7181 to digital output
trace to digital data receiver to digital ground plane to analog
ground plane.
VDD
10nF
GND
Figure 37. Recommend Power Supply Decoupling
100nF
VIA TO SUPPLY
VIA TO GND
04820-038
It is particularly important to maintain low noise and good
stability of PVDD. Careful attention must be paid to regulation,
filtering, and decoupling. It is highly desirable to provide
separate regulated supplies for each of the analog circuitry
groups (AVDD, DVDD, DVDDIO, and PVDD).
Some graphic controllers use substantially different levels of
power when active (during active picture time) and when idle
(during horizontal and vertical sync periods). This can result in
a measurable change in the voltage supplied to the analog
supply regulator, which can, in turn, produce changes in the
regulated analog supply voltage. This can be mitigated by
regulating the analog supply, or at least PVDD, from a different,
cleaner, power source, for example, from a 12 V supply.
PLL
Place the PLL loop filter components as close to the ELPF pin as
possible. Do not place any digital or other high frequency traces
near these components. Use the values suggested in the data
sheet with tolerances of 10% or less.
DIGITAL OUTPU TS ( B OTH DATA AND C LOCKS)
Try to minimize the trace length that the digital outputs have to
drive. Longer traces have higher capacitance, which requires
more current, which causes more internal digital noise. Shorter
traces reduce the possibility of reflections.
Adding a 30 Ω and 50 Ω series resistor can suppress reflections,
reduce EMI, and reduce the current spikes inside the ADV7181.
If series resistors are used, place them as close as possible to the
ADV7181 pins. However, try not to add vias or extra length to
the output trace to make the resistors closer.
If possible, limit the capacitance that each of the digital outputs
drives to less than 15 pF. This can easily be accomplished by
keeping traces short and by connecting the outputs to only one
device. Loading the outputs with excessive capacitance increases
the current transients inside the ADV7181, creating more
digital noise on its power supplies.
Rev. B | Page 96 of 104
ADV7181
DIGITAL INPUTS
The digital inputs on the ADV7181 were designed to work with
3.3 V signals, and are not tolerant of 5 V signals. Extra components are needed if 5 V logic signals are required to be applied
to the decoder.
Antialiasing Filters
For inputs from some video sources that are not bandwidth
limited, signals outside the video band can alias back into the
video band during A/D conversion and appear as noise on the
output video. The ADV7181 oversamples the analog inputs by
a factor of 4. This 54 MHz sampling frequency reduces the
requirement for an input filter; for optimal performance it is
recommended that an antialiasing filter be used. The
recommended low cost circuit for implementing this buffer and
filter circuit for all analog input signals is shown in Figure 41.
The buffer is a simple emitter-follower using a single npn
transistor. The antialiasing filter is implemented using passive
components. The passive filter is a third-order Butterworth
filter with a –3 dB point of 9 MHz. The frequency response of
the passive filter is shown in Figure 39. The flat pass band up to
6 MHz is essential. The attenuation of the signal at the output of
the filter due to the voltage divider of R24 and R63 is compensated for in the ADV7181 part using the automatic gain control.
The ac coupling capacitor at the input to the buffer creates a
high-pass filter with the biasing resistors for the transistor. This
filter has a cutoff of
{2 × π × (
R39||R89) × C93}
–1
= 0.62 Hz
It is essential that the cutoff of this filter be less than 1 Hz to
ensure correct operation of the internal clamps within the part.
These clamps ensure that the video stays within the 5 V range
of the op amp used.
0
XTAL AND LOAD CAPACITOR VALUE SELECTION
Figure 40 shows an example reference clock circuit for the
ADV7181. Special care must be taken when using a crystal
circuit to generate the reference clock for the ADV7181. Small
variations in reference clock frequency can cause autodetection
issues and impair the ADV7181 performance.
XTAL
27 MHz
33pF33pF
04820-040
Figure 40. Crystal Circuit
Use the following guidelines to ensure correct operation:
•
Use the correct frequency crystal, which is 27 MHz.
Tolerance should be 50 ppm or better.
Use a parallel-resonant crystal.
•
Know the C
•
value of Capacitors C1 and C2 must match C
specific crystal part number in the user’s system.
Examples of how to connect the ADV7181 video decoder are shown in Figure 41 and Figure 42.
AVDD_5V
R43
0Ω
C
B
E
470Ω
R24
FILTER
Q6
12µH
C95
22pF
L10
C102
10pF
R63
820Ω
C93
100µF
R38
75Ω
BUFFER
R39
4.7kΩ
R53
56Ω
R89
5.6kΩ
AGND
04820-042
Figure 41. ADI Recommended Antialiasing Circuit for All Input Channels
Rev. B | Page 98 of 104
ADV7181
AGND DGND
S-VIDEO
Y
Pr
Pb
CBVS
RECOMMENDED ANTI-ALIAS FILTER
CIRCUIT IS SHOWN IN FIGURE 40 ON THE
PREVIOUS PAGE. THIS CIRCUIT INCLUDES
A 75Ω TERMINATION RESISTOR, INPUT
BUFFER AND ANTI-ALIASING FILTER.
ANTI-ALIAS
FILTER CIRCUIT
ANTI-ALIAS
FILTER CIRCUIT
ANTI-ALIAS
FILTER CIRCUIT
ANTI-ALIAS
FILTER CIRCUIT
ANTI-ALIAS
FILTER CIRCUIT
ANTI-ALIAS
FILTER CIRCUIT
AGND
+
0.1µF
0.1µF
AGND
10µF0.1µF
DVDDIO
(3.3V)
PVDD
(1.8V)
AVDD
(3.3V)
DVDD
(1.8V)
75Ω
75Ω
+
+
75Ω
AGND
+
75Ω
0.1µF10µF
0.1µF
FERITE BEAD
33µF
DGND
FERITE BEAD
33µF
AGND
FERITE BEAD
33µF
AGND
FERITE BEAD
33µF
DGND
100nF
100nF
100nF
100nF
100nF
100nF
75Ω
75Ω
0.1µF10µF
0.1nF
0.1nF10µF
10µF
DGND
10µF
AGND
10µF
AGND
10µF
DGND
AIN2
AIN1
AIN3
AIN4
AIN5
AIN6
CAP Y1
CAP Y2
CAP C2
CML
REFOUT
AVDD
PVDD
DVDD
ADV7181
DVDDIO
LLC
0.1µF
DGND
0.1µF
AGND
0.1µF
AGND
0.1µF
DGND
P0
P1
P2
P3
P4
P5
P6
P7
P8
P9
P10
P11
P12
P13
P14
P15
POWER SUPPLY
0.01µF
DECOUPLING FOR
EACH POWER PIN
DGND
POWER SUPPLY
0.01µF
DECOUPLING FOR
EACH POWER PIN
AGND
POWER SUPPLY
0.01µF
DECOUPLING FOR
EACH POWER PIN
AGND
POWER SUPPLY
0.01µF
DECOUPLING FOR
EACH POWER PIN
DGND
MULTI
FORMAT
PIXEL
PORT
P15–P8 8-BIT ITU-R BT.656 PIXEL DATA @ 27MHz
P7–P0 Cb AND Cr 16-BIT ITU-R BT.656 PIXEL DATA @ 13.5MHz
P15–P8 Y1 AND Y2 16-BIT ITU-R BT.656 PIXEL DATA @ 13.5MHz
27MHz OUTPUT CLOCK
DVDDIO
2
SELECT I
C
ADDRESS
MPU INTERFACE
CONTROL LINES
DVSS
AGND
33pF
DGND
DVDDIO
DVDDIO DVDDIO
2kΩ2kΩ
DVDDIO
4.7kΩ
100nF
XTAL
27MHz
DGND
DGND
33pF
33Ω
33Ω
XTAL1
PWRDN
ALSB
SCLK
SDA
RESETRESET
FIELDFIELD O/P
ELPF
AGND DGND
AGND DGND
Figure 42. Typical Connection Diagram
Rev. B | Page 99 of 104
SFLSFL O/P
HSHS O/P
VSVS O/P
1.69kΩ10nF
82nF
PVDD
04820-041
ADV7181
OUTLINE DIMENSIONS
9.00
BSC SQ
PIN 1
INDICATOR
0.60 MAX
49
48
0.60 MAX
0.30
0.25
0.18
PIN 1
64
INDICATOR
1
1.00
0.85
0.80
1.45
1.40
1.35
12° MAX
SEATING
PLANE
0.15
SEATING
0.05
PLANE
VIEW A
ROTATED 90° CCW
TOP
VIEW
0.80 MAX
0.65 TYP
0.50 BSC
*
COMPLIANT TO JEDEC STANDARDS MO-220-VMMD
EXCEPT FOR EXPOSED PAD DIMENSION
8.75
BSC SQ
0.20 REF
0.45
0.40
0.35
0.05 MAX
0.02 NOM
33
32
Figure 43. 64-Lead Lead Frame Chip Scale Package [LFCSP]