FEATURES
ITU-R BT601/656 YCrCb to PAL/NTSC Video Encoder
High Quality 10-Bit Video DACs
Integral Nonlinearity <1 LSB at 10 Bits
NTSC-M, PAL-M/N, PAL-B/D/G/H/I
Single 27 MHz Clock Required (ⴛ2 Oversampling)
80 dB Video SNR
32-Bit Direct Digital Synthesizer for Color Subcarrier
Multistandard Video Output Support:
CCIR-656 4:2:2 8-Bit Parallel Input Format
4:2:2 16-Bit Parallel Input Format
Full Video Output Drive or Low Signal Drive Capability
34.7 mA max into 37.5 ⍀ (Doubly-Terminated 75R)
5 mA min with External Buffers
Programmable Simultaneous Composite
and S-Video Y/C or RGB (SCART)/YUV Video Outputs
Programmable Luma Filters (Low-Pass/Notch/Extended)
Programmable VBI (Vertical Blanking Interval)
Programmable Subcarrier Frequency and Phase
Programmable LUMA Delay
Individual ON/OFF Control of Each DAC
FUNCTIONAL BLOCK DIAGRAM
to PAL/NTSC Video Encoder
ADV7175A/ADV7176A*
CCIR and Square Pixel Operation
Integrated Subcarrier Locking to External Video Source
Color Signal Control/Burst Signal Control
Interlaced/Noninterlaced Operation
Complete On-Chip Video Timing Generator
Programmable Multimode Master/Slave Operation
Macrovision Antitaping Rev 7.01 (ADV7175A Only)**
Closed Captioning Support
Teletext Insertion Port (PAL-WST)
Onboard Color Bar Generation
Onboard Voltage Reference
2-Wire Serial MPU Interface (I
Single Supply 5 V or 3 V Operation
Small 44-Lead MQFP Thermally Enhanced Package
APPLICATIONS
MPEG-1 and MPEG-2 Video, DVD, Digital Satellite/
Cable Systems (Set Top Boxes/IRDs), Digital TVs,
CD Video/Karaoke, Video Games, PC Video/Multimedia
GENERAL DESCRIPTION
The ADV7175A/ADV7176A is an integrated digital video encoder
that converts Digital CCIR-601 4:2:2 8 or 16-bit component
video data into a standard analog baseband television signal
2
C Compatible)
(Continued on page 11)
*Protected by U.S. patents numbers 5,343,196 and 5,442,355 and other intellectual property rights.
**This device is protected by U.S. Patent Numbers 4631603, 4577216, 4819098 and other intellectual property rights. The Macrovision anticopy process is
licensed for noncommercial home use only, which is its sole intended use in the device. Please contact sales office for latest Macrovision version available.
NOTE: ITU-R and CCIR are used interchangeably in this document (ITU-R has replaced CCIR recommendations).
REV. C
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
Stopband Cutoff>54 dB Attenuation7.0MHz
Passband Cutoff F
3 dB
>3 dB Attenuation4.2MHz
Chroma BandwidthNTSC Mode
Stopband Cutoff>40 dB Attenuation3.2MHz
Passband Cutoff F
Luma Bandwidth
3 dB
3
(Low-Pass Filter)PAL Mode
>3 dB Attenuation2.0MHz
Stopband Cutoff>50 dB Attenuation7.4MHz
Passband Cutoff F
3 dB
>3 dB Attenuation5.0MHz
Chroma BandwidthPAL Mode
Stopband Cutoff>40 dB Attenuation4.0MHz
Passband Cutoff F
Differential Gain
Differential Phase
4
SNR
(Pedestal)RMS75dB rms
4
SNR
(Pedestal)Peak Periodic68dB p-p
4
(Ramp)RMS58dB rms
SNR
4
SNR
(Ramp)Peak Periodic56dB p-p
Hue Accuracy
Color Saturation Accuracy
Luminance Nonlinearity
Chroma AM Noise
Chroma PM Noise
Chroma AM Noise
Chroma PM Noise
NOTES
1
The max/min specifications are guaranteed over this range. The max/min values are typical over 3.0 V to 3.6 V.
2
Temperature range T
3
These specifications are for the low-pass filter only and guaranteed by design. For other internal filters, see Figure 4.
4
Guaranteed by characterization.
Specifications subject to change without notice.
3 dB
4
4
4
4
4
4
4
4
4
to T
MIN
: 0°C to 70°C.
MAX
>3 dB Attenuation2.4MHz
Normal Power Mode0.7%
Normal Power Mode0.5Degree
NTSC67dB
NTSC63dB
PAL64dB
PAL63dB
= 1.235 V, R
REF
= 300 ⍀. All specifications T
SET
MIN
to T
MinTypMaxUnit
1.0Degree
1.2%
1.1±%
MAX
2
–5–REV. C
ADV7175A/ADV7176A
to T
MAX
2
unless
5 V TIMING SPECIFICATIONS
(VAA = 4.75 V–5.25 V1, V
otherwise noted.)
= 1.235 V, R
REF
= 150 ⍀. All specifications T
SET
MIN
ParameterConditionsMinTypMaxUnit
MPU PORT
3, 4
SCLOCK Frequency0100kHz
SCLOCK High Pulsewidth, t
SCLOCK Low Pulsewidth, t
Hold Time (Start Condition), t
Setup Time (Start Condition), t
Data Setup Time, t
5
SDATA, SCLOCK Rise Time, t
SDATA, SCLOCK Fall Time, t
Setup Time (Stop Condition), t
ANALOG OUTPUTS
3, 5
1
2
After This Period the First Clock Is Generated4.0µs
3
Relevant for Repeated Start Condition4.7µs
4
6
7
8
4.0µs
4.7µs
250ns
1µs
300ns
4.7µs
Analog Output Delay5ns
DAC Analog Output Skew0ns
CLOCK CONTROL
AND PIXEL PORT
F
CLOCK
Clock High Time, t
Clock Low Time, t
Data Setup Time, t
Data Hold Time, t
Control Setup Time, t
Control Hold Time, t
Digital Output Access Time, t
Digital Output Hold Time, t
Pipeline Delay, t
TELETEXT PORT
Digital Output Access Time, t
Data Setup Time, t
Data Hold Time, t
RESET CONTROL
3, 6
27MHz
9
10
11
12
11
12
13
14
15
3, 7
16
17
18
3, 4
8ns
8ns
3.5ns
4ns
4ns
3ns
24ns
4ns
37Clock Cycles
20ns
1ns
2ns
RESET Low Time6ns
NOTES
1
The max/min specifications are guaranteed over this range.
2
Temperature range T
3
TTL input values are 0 to 3 volts, with input rise/fall times ≤ 3 ns, measured between the 10% and 90% points. Timing reference points at 50% for inputs and
outputs. Analog output load ≤ 10 pF.
4
Guaranteed by characterization.
5
Output delay measured from the 50% point of the rising edge of CLOCK to the 50% point of full-scale transition.
6
Pixel Port consists of the following:
Pixel Inputs:P15–P0
Pixel Controls:HSYNC, FIELD/VSYNC, BLANK
Clock Input:CLOCK
7
Teletext Port consists of the following:
Teletext Output:TTXREQ
Teletext Input:TTX
Specifications subject to change without notice.
MIN
to T
: 0°C to 70°C.
MAX
–6–
REV. C
ADV7175A/ADV7176A
2
to T
unless
MAX
1µs
300ns
24ns
3.3 V TIMING SPECIFICATIONS
(VAA = 3.0–3.61, V
otherwise noted.)
= 1.235 V, R
REF
= 300 ⍀. All specifications T
SET
MIN
ParameterConditionsMinTypMaxUnit
MPU PORT
3, 4
SCLOCK Frequency0100kHz
SCLOCK High Pulsewidth, t
SCLOCK Low Pulsewidth, t
Hold Time (Start Condition), t
Setup Time (Start Condition), t
Data Setup Time, t
5
SDATA, SCLOCK Rise Time, t
SDATA, SCLOCK Fall Time, t
Setup Time (Stop Condition), t
ANALOG OUTPUTS
3, 5
1
2
3
After This Period the First Clock Is Generated4.0µs
for Repeated Start Condition4.7µs
4
6
7
8
4.0µs
4.7µs
250ns
4.7µs
Analog Output Delay7ns
DAC Analog Output Skew0ns
CLOCK CONTROL
AND PIXEL PORT
F
CLOCK
Clock High Time, t
Clock Low Time, t
Data Setup Time, t
Data Hold Time, t
Control Setup Time, t
Control Hold Time, t
Digital Output Access Time, t
Digital Output Hold Time, t
Pipeline Delay, t
TELETEXT PORT
Digital Output Access Time t
Data Setup Time, t
Data Hold Time, t
RESET CONTROL
3, 4, 6, 7
10
12
15
3, 6, 8
18
3, 4
27MHz
9
8ns
8ns
11
3.5ns
4ns
11
12
13
14
4ns
3ns
4ns
37Clock Cycles
16
17
23ns
2ns
2ns
RESET Low Time6ns
NOTES
1
The max/min specifications are guaranteed over this range.
2
Temperature range T
3
TTL input values are 0 to 3 volts, with input rise/fall times ≤ 3 ns, measured between the 10% and 90% points. Timing reference points at 50% for inputs and
outputs. Analog output load ≤ 10 pF.
4
Guaranteed by characterization.
5
Output delay measured from the 50% point of the rising edge of CLOCK to the 50% point of full-scale transition.
6
Characterized by design.
7
Pixel Port consists of the following:
Pixel Inputs:P15–P0
Pixel Controls:HSYNC, FIELD/VSYNC, BLANK
Clock Input:CLOCK
8
Teletext Port consists of the following:
Teletext Output:TTXREQ
Teletext Input:TTX
Lead Temperature (Soldering, 10 secs) . . . . . . . . . . . . 260°C
Analog Outputs to GND2 . . . . . . . . . . . . . GND – 0.5 to V
NOTES
1
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 listed in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for
extended periods may affect device reliability.
2
Analog output short circuit to any power supply or common can be of an indefinite
duration.
AA
ORDERING GUIDE
Temperature PackagePackage
ModelRangeDescriptionOption
ADV7175AKS 0°C to 70°CPlastic Quad Flatpack S-44
ADV7176AKS 0°C to 70°CPlastic Quad Flatpack S-44
PIN CONFIGURATION
PACKAGE THERMAL PERFORMANCE
The 44-MQFP package used for this device takes advantage of
an ADI patented thermal coastline lead frame construction.
This maximizes heat transfer into the leads and reduces the
package thermal resistance.
The junction-to-ambient (θ
) thermal resistance in still air on a
JA
four-layer PCB is 35.5°C/W. The junction-to-case thermal
resistance (θ
) is 13.75°C/W.
JC
AA
SET
TTXREQ/GND
R
SCRESET/
RTC
35 3437
33
32
31
30
29
28
27
26
25
24
23
AA
V
GND
RESET
V
REF
DAC A
DAC B
V
AA
GND
V
AA
DAC D
DAC C
COMP
SDATA
SCLOCK
V
P5
P6
P7
P8
P9
P10
P11
P12
GND
V
AA
P3
GND
CLOCK
434436
1
AA
PIN 1
IDENTIFIER
2
3
4
5
6
7
8
9
10
11
121314 15 16 17 18 192021 2 2
P14
P13
P2
P4
42
40
39 3841
ADV7175A/ADV7176A
MQFP
TOP VIEW
(Not to Scale)
P15
HSYNC
FIELD/VSYNC
P1
P0
ALSB
BLANK
TTX/V
GND
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 the ADV7175A/ADV7176A feature 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.
WARNING!
ESD SENSITIVE DEVICE
–9–REV. C
ADV7175A/ADV7176A
PIN FUNCTION DESCRIPTIONS
PinInput/
No.MnemonicOutputFunction
1, 11, 20,
28, 30V
AA
10, 19, 21,
29, 43GNDGGround Pin.
15HSYNCI/OHSYNC (Modes 1 and 2) Control Signal. This pin may be configured to
16FIELD/VSYNCI/ODual Function FIELD (Mode 1) and VSYNC (Mode 2) Control Signal. This
17BLANKI/OVideo Blanking Control Signal. The pixel inputs are ignored when this is
18ALSBITTL Address Input. This signal sets up the LSB of the MPU address.
22RESETIThe input resets the on chip timing generator and sets the ADV7175A/
23SCLOCKIMPU Port Serial Interface Clock Input.
24SDATAI/OMPU Port Serial Data Input/Output.
25COMPOCompensation Pin. Connect a 0.1 µF capacitor from COMP to V
26DAC CORED/S-Video C/V Analog Output.
27DAC DOGREEN/S-Video Y/Y Analog Output.
31DAC BOBLUE/Composite/U Analog Output.
32DAC AOPAL/NTSC Composite Video Output. Full-Scale Output is 180IRE (1286
33V
34R
REF
SET
35SCRESET/RTCIThis pin can be configured as an input by setting MR22 and MR21 of Mode
36TTXREQ/GNDOTeletext Data Request Signal/Defaults to GND when Teletext not selected
37TTX/V
AA
38–42P0–P15I8-Bit 4:2:2 Multiplexed YCrCb Pixel Port (P7–P0) or
2–9, 12–1416-Bit YCrCb Pixel Port (P0–P15). P0 represents the LSB.
44CLOCKITTL Clock Input. Requires a stable 27 MHz reference Clock for standard
PPower Supply (3 V to 5 V).
output (Master Mode) or accept (Slave Mode) Sync signals.
pin may be configured to output (Master Mode) or accept (Slave Mode)
these control signals.
logic level “0.” This signal is optional.
ADV7176A into default mode. This is NTSC operation, Timing Slave Mode
0, 8-bit operation, 2 × composite and S-Video out and all DACs powered on.
. For
AA
Optimum Dynamic Performance in Low Power Mode, the value of the
COMP capacitor can be lowered to as low as 2.2 nF.
mV) for NTSC and 1300 mV for PAL.
I/OVoltage Reference Input for DACs or Voltage Reference Output (1.235 V).
IA 150 Ω resistor connected from this pin to GND is used to control full-scale
amplitudes of the video signals.
Register 2. It can be configured as a subcarrier reset pin, in which case a lowto-high transition on this pin will reset the subcarrier to Field 0. Alternatively
it may be configured as a Real Time Control (RTC) input.
(enables backward compatibility to ADV7175/ADV7176).
ITeletext Data/Defaults to VAA when Teletext not selected (enables backward
compatibility to ADV7175/ADV7176).
operation. Alternatively, a 24.5454 MHz (NTSC) or 29.5 MHz (PAL) can be
used for square pixel operation.
–10–
REV. C
ADV7175A/ADV7176A
(Continued from page 1)
compatible with worldwide standards. The 4:2:2 YUV video
data is interpolated to two times the pixel rate. The colordifference components (UV) are quadrature modulated using
a subcarrier frequency generated by an on-chip 32-bit digital
synthesizer (also running at two times the pixel rate). The two
times pixel rate sampling allows for better signal-to-noise-ratio.
A 32-bit DDS with a 10-bit look-up table produces a superior
subcarrier in terms of both frequency and phase. In addition to
the composite output signal, there is the facility to output SVideo (Y/C) video, YUV or RGB video. The Y/C, YUV or RGB
format is simultaneously available at the analog outputs with the
composite video signal.
Each analog output is capable of driving the full video-level
(35 mA) signal into an unbuffered, doubly terminated 75 Ω
load. With external buffering, the user has the additional option
to scale back the DAC output current to 5 mA min, thereby significantly reducing the power dissipation of the device.
The ADV7175A/ADV7176A also supports both PAL and NTSC
square pixel operation.
The output video frames are synchronized with the incoming
data timing reference codes. Optionally the encoder accepts
(and can generate) HSYNC, VSYNC and FIELD timing signals.
These timing signals can be adjusted to change pulsewidth and
position while the part is in the master mode. The encoder
requires a single two times pixel rate (27 MHz) clock for standard
operation. Alternatively, the encoder requires a 24.5454 MHz
clock for NTSC or 29.5 MHz clock for PAL square pixel
mode operation. All internal timing is generated on-chip.
A separate teletext port enables the user to directly input teletext
data during the vertical blanking interval.
The ADV7175A/ADV7176A modes are set up over a two-wire
serial bidirectional port (I
2
C Compatible) with two slave addresses.
Functionally the ADV7175A and ADV7176A are the same with
the exception that the ADV7175A can output the Macrovision
anticopy algorithm.
The ADV7175A/ADV7176A is packaged in a 44-lead thermally
enhanced MQFP package.
DATA PATH DESCRIPTION
For PAL B, D, G, H, I, M, N and NTSC M modes, YCrCb
4:2:2 data is input via the CCIR-656 compatible pixel port at a
27 MHz Data Rate. The pixel data is demultiplexed to from
three data paths. Y typically has a range of 16 to 235, Cr and
Cb typically have a range of 128 ± 112; however, it is possible to input data from 1 to 254 on both Y, Cb and Cr. The
ADV7175A/ADV7176A supports PAL (B, D, G, H, I, N, M)
and NTSC (with and without Pedestal) standards. The appropriate SYNC, BLANK and Burst levels are added to the YCrCb
data. Macrovision antitaping (ADV7175A only), closed captioning and teletext levels are also added to Y, and the resultant
data is interpolated to a rate of 27 MHz. The interpolated data
is filtered and scaled by three digital FIR filters.
The U and V signals are modulated by the appropriate subcarrier
sine/cosine phases and added together to make up the chrominance signal. The luma (Y) signal can be delayed 1–3 luma
cycles (each cycle is 74 ns) with respect to the chroma signal.
The luma and chroma signals are then added together to make
up the composite video signal. All edges are slew rate limited.
The YCrCb data is also used to generate RGB data with
appropriate SYNC and BLANK levels. The RGB data is in
synchronization with the composite video output. Alternatively
analog YUV data can be generated instead of RGB.
The four 10-bit DACs can be used to output:
1. Composite Video + RGB Video.
2. Composite Video + YUV Video
3. Two Composite Video Signals + LUMA and CHROMA
3. (Y/C) Signals.
Alternatively, each DAC can be individually powered off if
not required.
Video output levels are illustrated in Appendix 4 and Appendix 5.
INTERNAL FILTER RESPONSE
The Y filter supports several different frequency responses,
including two 4.5 MHz/5.0 MHz low pass responses, PAL/
NTSC subcarrier notch responses and a PAL/NTSC extended
response. The U and V filters have a 2/2.4 MHz low-pass
response for NTSC/PAL. These filter characteristics are illustrated in Figures 4 to 12.
The ADV7175A/ADV7176A can be configured to generate
100/7.5/75/7.5 for NTSC color bars or 100/0/75/0 for PAL
color bars. These are enabled by setting MR17 of Mode Register 1 to Logic “1.”
SQUARE PIXEL MODE
The ADV7175A/ADV7176A can be used to operate in square
pixel mode. For NTSC operation an input clock of 24.5454 MHz
is required. Alternatively an input clock of 29.5 MHz is required
for PAL operation. The internal timing logic adjusts accordingly
for square pixel mode operation.
COLOR SIGNAL CONTROL
The color information can be switched on and off the video
output using Bit MR24 of Mode Register 2.
BURST SIGNAL CONTROL
The burst information can be switched on and off the video
output using Bit MR25 of Mode Register 2.
NTSC PEDESTAL CONTROL
The pedestal on both odd and even fields can be controlled on a
line-by-line basis using the NTSC Pedestal Control Registers.
This allows the pedestals to be controlled during the vertical
blanking interval (Lines 10 to 25 and Lines 273 to 288).
PIXEL TIMING DESCRIPTION
The ADV7175A/ADV7176A can operate in either 8-bit or
16-bit YCrCb Mode.
8-Bit YCrCb Mode
This default mode accepts multiplexed YCrCb inputs through
the P7-P0 pixel inputs. The inputs follow the sequence Cb0, Y0
Cr0, Y1 Cb1, Y2, etc. The Y, Cb and Cr data are input on a
rising clock edge.
16-Bit YCrCb Mode
This mode accepts Y inputs through the P7–P0 pixel inputs and
multiplexed CrCb inputs through the P15–P8 pixel inputs. The
data is loaded on every second rising edge of CLOCK. The inputs
follow the sequence Cb0, Y0 Cr0, Y1 Cb1, Y2, etc.
SUBCARRIER RESET
Together with the SCRESET/RTC PIN and Bits MR22 and
MR21 of Mode Register 2, the ADV7175A/ADV7176A can be
used in subcarrier reset mode. The subcarrier will reset to
Field 0 at the start of the following field when a low to high
transition occurs on this input pin.
REAL TIME CONTROL
Together with the SCRESET/RTC PIN and Bits MR22 and
MR21 of Mode Register 2, the ADV7175A/ADV7176A can be
used to lock to an external video source. The real time control
mode allows the ADV7175A/ADV7176A to automatically alter
the subcarrier frequency to compensate for line length variation.
When the part is connected to a device that outputs a digital
datastream in the RTC format (such as an ADV7185 video
decoder [see Figure 13]), the part will automatically change to
the compensated subcarrier frequency on a line by line basis.
This digital datastream is 67 bits wide and the subcarrier is
contained in Bits 0 to 21. Each bit is two clock cycles long.
00HEX should be written to all four subcarrier frequency registers when using this mode.
VIDEO TIMING DESCRIPTION
The ADV7175A/ADV7176A is intended to interface to offthe-shelf MPEG1 and MPEG2 Decoders. Consequently, the
ADV7175A/ADV7176A accepts 4:2:2 YCrCb Pixel Data via a
CCIR-656 pixel port and has several video timing modes of
operation that allow it to be configured as either system master
video timing generator or a slave to the system video timing
generator. The ADV7175A/ADV7176A generates all of the
required horizontal and vertical timing periods and levels for the
analog video outputs.
The ADV7175A/ADV7176A calculates the width and placement of analog sync pulses, blanking levels and color burst
envelopes. Color bursts are disabled on appropriate lines, and
serration and equalization pulses are inserted where required.
In addition the ADV7175A/ADV7176A supports a PAL or
NTSC square pixel operation in slave mode. The part requires
an input pixel clock of 24.5454 MHz for NTSC and an input
pixel clock of 29.5 MHz for PAL. The internal horizontal line
counters place the various video waveform sections in the correct location for the new clock frequencies.
The ADV7175A/ADV7176A has four distinct master and four
distinct slave timing configurations. Timing Control is established with the bidirectional SYNC, BLANK and FIELD/
VSYNC pins. Timing Mode Register 1 can also be used to vary
the timing pulsewidths and where they occur in relation to
each other.
–13–REV. C
ADV7175A/ADV7176A
COMPOSITE
VIDEO
e.g., VCR
OR CABLE
H/LTRANSITION
COUNT START
RTC
LOW
128
DECODER
ADV7185
13
LLC1
VIDEO
14 BITS
RESERVED
GLL
P19–P12
RESERVED
0
4 BITS
21
CLOCK
SCRESET/RTC
GREEN/LUMA/Y
P7–P0
HSYNC
VSYNC/FIELD
RED/CHROMA/V
BLUE/COMPOSITE/U
COMPOSITE
ADV7175A/ADV7176A
FSCPLL INCREMENT
SEQUENCE
2
5 BITS
RESERVED
1
BIT
0
RESET
BIT
RESERVED
3
TIME SLOT: 01
NOTES:
1
FSC PLL INCREMENT IS 22 BITS LONG, VALUED LOADED INTO ADV7175A/ADV7176A FSC DDS REGISTER IS
F
PLL INCREMENTS BITS 21:0 PLUS BITS 0:9 OF SUB CARRIER FREQUENCY REGISTERS. ALL ZEROS SHOULD
SC
BE WRITTEN TO THE SUB CARRIER FREQUENCY REGISTERS OF THE ADV7175A/ADV7176A.
2
SEQUENCE BIT
PAL: 0 = LINE NORMAL, 1 = LINE INVERTED
NTSC: 0 = NO CHANGE.
3
RESET BIT
RESET ADV7175A/ADV7176A’s DDS.
NOT USED IN
ADV7175A/ADV7176A
19
14
VALID
SAMPLE
INVALID
SAMPLE
8/LLC
67 68
Figure 13. RTC Timing and Connections
Vertical Blanking Data Insertion
It is possible to allow encoding of incoming YCbCr data on those lines of VBI that do not bear line sync or pre/post-equalization
pulses (see Figures 15 to 26). This mode of operation is called “Partial Blanking” and is selected by setting MR31 to 1. It allows the
insertion of any VBI data (Opened VBI) into the encoded output waveform. This data is present in digitized incoming YCbCr data
stream (e.g., WSS data, CGMS, VPS, etc.). Alternatively, the entire VBI may be blanked (no VBI data inserted) on these lines by
setting MR31 to 0.
Mode 0 (CCIR-656): Slave Option
(Timing Register 0 TR0 = X X X X X 0 0 0)
The ADV7175A/ADV7176A is controlled by the SAV (Start Active Video) and EAV (End Active Video) time codes in the pixel
data. All timing information is transmitted using a 4-byte synchronization pattern. A synchronization pattern is sent immediately
before and after each line during active picture and retrace. Mode 0 is illustrated in Figure 14. The HSYNC, FIELD/VSYNC andBLANK (if not used) pins should be tied high during this mode.
–14–
REV. C
ANALOG
VIDEO
ADV7175A/ADV7176A
INPUT PIXELS
NTSC/PAL M SYSTEM
(525 LlNES/60Hz)
PAL SYSTEM
(625 LINES/50Hz)
EAV CODE
C
FF0000X
Y
Y
r
4 CLOCK
4 CLOCK4 CLOCK
END OF ACTIVE
VIDEO LINE
8
10801
0
Y
0
FF00FFABABA
ANCILLARY DATA
268 CLOCK
280 CLOCK
B
(HANC)
801
0
SAV CODE
8
10FF0
0
0
XYC
Y
0
0
b
4 CLOCK
START OF ACTIVE
VIDEO LINE
C
C
Y
Y
b
r
1440 CLOCK
1440 CLCOK
C
C
Y
b
r
Figure 14. Timing Mode 0 (Slave Mode)
Mode 0 (CCIR-656): Master Option
(Timing Register 0 TR0 = X X X X X 0 0 1)
The ADV7175A/ADV7176A generates H, V and F signals required for the SAV (Start Active Video) and EAV (End Active Video)
time codes in the CCIR-656 standard. The H bit is output on the HSYNC pin, the V bit is output on the BLANK pin, and the F bit
is output on the FIELD/VSYNC pin. Mode 0 is illustrated in Figure 15 (NTSC) and Figure 16 (PAL). The H, V and F transitions
relative to the video waveform are illustrated in Figure 17.
DISPLAY
5225235245251234
H
V
VERTICAL BLANK
67
5
1011202122
9
8
DISPLAY
F
DISPLAY
260261262263264265266267268269270271272273274
H
V
F
ODD FIELDEVEN FIELD
ODD FIELDEVEN FIELD
VERTICAL BLANK
Figure 15. Timing Mode 0 (NTSC Master Mode)
283
284
DISPLAY
285
–15–REV. C
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