Analog/HDMI dual interface
Supports high bandwidth digital content protection
RGB-to-YCbCr 2-way color conversion
Automated clamping level adjustment
1.8 V/3.3 V power supply
100-lead LQFP Pb-free package
RGB and YCbCr output formats
Analog interface
8-bit triple ADC
100 MSPS maximum conversion rate
Macrovision® detection
2:1 input mux
Full sync processing
Sync detect for hot plugging
Midscale clamping
Digital video interface
HDMI v 1.1, DVI v 1.0
150 MH
Supports high bandwidth digital content protection
(HDCP 1.1)
Digital audio interface
HDMI 1.1-compatible audio interface
S/PDIF (IEC90658-compatible) digital audio output
Multichannel I2S audio output (up to 8 channels)
APPLICATIONS
Advanced TV
HDTV
Projectors
LCD monitor
GENERAL DESCRIPTION
The AD9880 offers designers the flexibility of an analog interface
and high definition multimedia interface (HDMI) receiver integrated on a single chip. Also included is support for high bandwidth digital content protection (HDCP).
Analog Interface
The AD9880 is a complete 8-bit 150 MSPS monolithic analog interface o
graphics signals. Its 150 MSPS encode rate capability and full power
analog bandwidth of 330 MHz supports all HDTV formats (up to
1080 p) and FPD resolutions up to SXGA (1280 × 1024 @ 75 Hz).
The analog interface includes a 150 MHz triple ADC with internal
1.25
gain, offset, and clamp control. The user provides only 1.8 V and
3.3 V power supplies, analog input, and Hsync. Three-state
Rev. 0
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.
z HDMI receiver
ptimized for capturing component video (YPbPr) and RGB
V reference, a phase-locked loop (PLL), and programmable
Dual Display Interface
AD9880
FUNCTIONAL BLOCK DIAGRAM
COAST
FILT
CKINV
CKEXT
SCL
SDA
RX0+
RX0–
RX1+
RX1–
RX2+
RX2–
RXC+
RXC–
R
TERM
MCL
MDA
IN0
IN1
ANALOG INTERFACE
2:1
CLAMP
MUX
2:1
MUX
2:1
MUX
2:1
MUX
POWER MANAGEMENT
DIGITAL INTERFACE
SYNC
PROCESSING
AND
CLOCK
GENERATION
SERIAL REGISTER
AND
HDMI RECEIVER
HDCP
A/D
REFOUT
REFIN
Figure 1.
2
4
R/G/B 8X3
or YCbCr
2
DATACK
HSOUT
VSOUT
SOGOUT
REF
R/G/B 8X3
OR YCbCr
DATACK
DE
H
SYNC
V
SYNC
MUXES
AD9880
R/G/B OR YPbPr
R/G/B OR YPbPr
HSYNC 0
HSYNC 1
HSYNC 0
HSYNC 1
SOGIN 0
SOGIN 1
DDCSCL
DDCSDA
CMOS outputs can be powered from 1.8 V to 3.3 V. The
AD9880’s on-chip PLL generates a pixel clock from Hsync. Pixel
clock output frequencies range from 12 MHz to 150 MHz. PLL
clock jitter is typically less than 700 ps p-p at 150 MHz. The
AD9880 also offers full sync processing for composite sync and
sync-on-green (SOG) applications.
Digital Interface
The AD9880 contains a HDMI 1.1-compatible receiver and supp
orts all HDTV formats (up to 1080 p and 720 p) and display
resolutions up to SXGA (1280 × 1024 @75 Hz). The receiver
features an intrapair skew tolerance of up to one full clock cycle.
With the inclusion of HDCP, displays can now receive encrypted
video content. The AD9880 allows for authentication of a video
receiver, decryption of encoded data at the receiver, and renewability of the authentication during transmission, as specified by the
HDCP v 1.1 protocol.
Fabricated in an advanced CMOS process, the AD9880 is provided
AD9880KSTZ-100 AD9880KSTZ-150
Parameter Temp Test Level Min Typ Max Min Typ Max Unit
RESOLUTION 8 8 Bits
DC ACCURACY
Differential Nonlinearity 25°C I –0.6
Integral Nonlinearity 25°C I ±1.0 ±2.1 ±1.1 ±2.25 LSB
No Missing Codes Full Guaranteed Guaranteed
ANALOG INPUT
Input Voltage Range
Minimum Full VI 0.5 0.5 V p–p
Maximum Full VI 1.0 1.0 V p–p
Gain Tempco +25°C V 100 220 ppm/°C
Input Bias Current +25°C V 0.2 1 μA
Input Full-Scale Matching
Offset Adjustment Range Full V 50 50 %FS
SWITCHING PERFORMANCE
Maximum Conversion Rate Full VI 100 150 MSPS
Minimum Conversion Rate Full VI 10 10 MSPS
Data to Clock Skew Full IV −0.5 +2.0 −0.5 +2.0 ns
Serial Port Timing
t
BUFF
t
STAH
t
DHO
t
DAL
t
DAH
t
DSU
t
STASU
t
STOSU
HSYNC Input Frequency Full VI 15 110 15 110 KHz
Maximum PLL Clock Rate Full VI 100 150 MHz
Minimum PLL Clock Rate Full IV 12 12 MHz
PLL Jitter +25°C IV 700 700 ps p-p
Sampling Phase Tempco Full IV 15 15 ps/°C
DIGITAL INPUTS: (5V tolerant)
Input Voltage, High (VIH) Full VI 2.6 2.6 V
Input Voltage, Low (VIL) Full VI 0.8 0.8 V
Input Current, High (IIH) Full V -82 -82 μA
Input Current, Low (IIL) Full V 82 82 μA
Input Capacitance 25°C V 3 3 pF
DIGITAL OUTPUTS
Output Voltage, High (VOH) Full VI VDD − 0.1 VDD − 0.1 V
Output Voltage, Low (VOL) Full VI 0.4 0.4 V
Duty Cycle, DATACK Full V 45 50 55 45 50 55 %
Output Coding Binary Binary
POWER SUPPLY
VD Supply Voltage Full IV 3.15 3.3 3.47 3.15 3.3 3.47 V
DVDD Supply Voltage Full IV 1.7 1.8 1.9 1.7 1.8 1.9 V
25C
ull
F
1
Full VI 4.7 4.7 μs
Full VI 4.0 4.0 μs
Full VI 0 0 μs
Full VI 4.7 4.7 μs
Full VI 4.0 4.0 μs
Full VI 250 250 ns
Full VI 4.7 4.7 μs
Full VI 4.0 4.0 μs
VI
VI
1.25
1.50
+1.6/–
1.0
5
7
±0.7
1.25
1.50
+1.8/–
1.0
5
7
LSB
%FS
%FS
Rev. 0 | Page 3 of 64
AD9880
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AD9880KSTZ-100 AD9880KSTZ-150
Parameter Temp Test Level Min Typ Max Min Typ Max Unit
VDD Supply Voltage Full IV 1.7 3.3 3.47 1.7 3.3 3.47 V
PVDD Supply Voltage Full IV 1.7 1.8 1.9 1.7 1.8 1.9 V
ID Supply Current (VD) 25°C VI 260 300 330 mA
I
Supply Current (DVDD) 25°C VI 45 60 85
DVDD
IDD Supply Current (VDD)
IP
Supply Current (P
VDD
Total Power Full VI 1.1 1.4 1.15 1.4 W
Power-Down Dissipation Full VI 130 130 mW
DYNAMIC PERFORMANCE
Analog Bandwidth, Full
Power
Signal–to–Noise Ratio (SNR) 25°C I 46 46 dB
Without Harmonics Full V 45 45 dB
fIN = 40.7 MHz
Crosstalk Full V 60 60 dBc
THERMAL CHARACTERISTICS
θJA-Junction-to-Ambient V 35 35 °C/W
1
Drive strength = high.
2
DATACK load = 15 pF, data load = 5 pF.
3
Specified current and power values with a worst case pattern (on/off).
High-Level Input Voltage, (VIH) VI 2.5 2.5 V
Low-Level Input Voltage, ( VIL) VI 0.8 0.8 V
High-Level Output Voltage, (VOH) VI VDD − 0.1 V
Low-Level Output Voltage, (VOL) VI VDD − 0.1 0.1 0.1 V
DC SPECIFICATIONS
Output High Level IV Output drive = high 36 36 mA
(I
) (V
OHD
= VOH) IV Output drive = low 24 24 mA
OUT
Output Low Level IV Output drive = high 12 12 mA
I
, (V
OLD
= VOL) IV Output drive = low 8 8 mA
OUT
DATACK High Level IV Output drive = high 40 40 mA
V
, (V
OHC
= VOH) IV Output drive = low 20 20 mA
OUT
DATACK Low Level IV Output drive = high 30 30 mA
V
, (V
OLC
Differential Input Voltage, Single Ended
= VOL) IV Output drive = low 15 15 mA
OUT
IV 75 700 75 700 mV
Amplitude
Rev. 0 | Page 4 of 64
AD9880
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AD9880KSTZ-100
AD9880KSTZ-150
Te st
Parameter
Level
Conditions Min Typ Max Min Typ Max Unit
POWER SUPPLY
VD Supply Voltage IV 3.15 3.3 3.47 3.15 3.3 3.47 V
VDD Supply Voltage IV 1.7 3.3 347 1.7 3.3 347 V
DVDD Supply Voltage IV 1.7 1.8 1.9 1.7 1.8 1.9 V
PVDD Supply Voltage IV 1.7 1.8 1.9 1.7 1.8 1.9 V
IVD Supply Current (Typical Pattern)
I
Supply Current (Typical Pattern)
VDD
I
Supply Current (Typical Pattern)
DVDD
I
Supply Current (Typical Pattern)
PVDD
1
V 80 100 80 110 mA
2
V 40 1003 55 175*
1, 4
V 88 110 110 145 mA
1
V 26 35 30 40 mA
Power-Down Supply Current (IPD) VI 130 130 mA
AC SPECIFICATIONS
Intrapair (+ to −) Differential Input Skew
)
(T
DPS
Channel to Channel Differential Input
CCS
)
Skew (T
Low-to-High Transition Time for Data and
Controls (D
LHT
)
IV
Low-to-High Transition Time for
DATACK (D
LHT
)
IV
IV 360 pS
IV 6
IV
Output drive = high;
900 ps
CL = 10 pF
1300 ps
650 ps
1200 ps
IV
Output drive = low;
= 5 pF
C
L
Output drive = high;
= 10 pF
C
L
Output drive = low;
CL = 5 pF
High-to-Low Transition Time for Data and
Controls (D
HLT
)
IV
High-to-Low Transition Time for
DATACK (D
HLT
)
IV
Clock to Data Skew5 (T
Duty Cycle, DATACK
DATACK Frequency (F
1
The typical pattern contains a gray scale area, output drive = high. Worst case pattern is alternating black and white pixels.
2
The typical pattern contains a gray scale area, output drive = high.
3
Specified current and power values with a worst case pattern (on/off).
4
DATACK load = 10 pF, data load = 5 pF.
5
Drive strength = high.
) IV –0.5 2.0 –0.5 2.0 ns
SKEW
5
) VI 20 150 MHz
CIP
IV
Output drive = high;
= 10 pF
C
L
Output drive = low;
= 5 pF
C
L
IV
Output drive = high;
= 10 pF
C
L
Output drive = low;
= 5 pF
C
L
IV 45 50 55 %
850 ps
1250 ps
800 ps
1200 ps
Clock
riod
Pe
Rev. 0 | Page 5 of 64
AD9880
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ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
VD 3.6 V
VDD 3.6 V
DVDD 1.98 V
PVDD 1.98 V
Analog Inputs VD to 0.0 V
Digital Inputs 5 V to 0.0 V
Digital Output Current 20 mA
Operating Temperature −25°C to + 85°C
Storage Temperature −65°C to + 150°C
Maximum Junction Temperature 150°C
Maximum Case Temperature 150°C
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
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
EXPLANATION OF TEST LEVELS
Tes t Le v el
I. 100% production tested.
II. 100% p
specified temperatures.
III. S
IV. P
V. P
VI. 100% p
ample tested only.
arameter is guaranteed by design and
characterization testing.
arameter is a typical value only.
and characterization testing.
roduction tested at 25°C and sample tested at
roduction tested at 25°C; guaranteed by design
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.
Rev. 0 | Page 6 of 64
AD9880
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PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
AIN0
AIN1
VDDRED 0
99
100
RED 1
98
RED 2
97
RED 3
96
RED 4
95
RED 5
94
RED 6
93
RED 7
92
GND
91
VDDDATACLKDEHSOUT
898887
90
SOGOUT
VSOUT
86
85
O/E FIELD
SDA
SCL
84
82
83
PWRDN
81
VDR
80
79
GND
R
787776
D
V
GND
GREEN 7
GREEN 6
GREEN 5
GREEN 4
GREEN 3
GREEN 2
GREEN 1
GREEN 0
V
GND
BLUE 7
BLUE 6
BLUE 5
BLUE 4
BLUE 3
BLUE 2
BLUE 1
BLUE 0
MCLKIN
MCLKOUT
SCLK
LRCLK
I2S3
I2S2
1
2
3
4
5
6
7
8
9
10
DD
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
PIN 1
26
I2S1
27
I2S0
AD9880
TOP VIEW
(Not to Scale)
31
33
GND
32
DV
34
D
DD
V
RX0–
29
30
28
DD
GND
DV
S/PDIF
37
38
39
42
35
36
GND
RX0+
40
GND
RX1–
RX2–
RX1+
44
41
43
GND
RX2+
RxC–
RxC+
48
45
46
47
D
V
DD
GND
DV
RTERM
Figure 2. Pin Configuration
75
GND
74
G
AIN0
73
SOGIN0
72
V
D
71
G
AIN1
70
SOGIN1
69
GND
68
B
AIN0
67
V
D
66
B
AIN1
65
GND
64
HSYNC 0
63
HSYNC 1
62
EXTCLK/COAST
61
VSYNC 0
60
VSYNC 1
59
PV
DD
58
GND
57
FILT
56
PV
DD
55
GND
54
PV
DD
53
ALGND
52
MDA
51
MCL
49
50
DDC_SCL
DDC_SDA
05087-002
Table 4. Complete Pinout List
Pin Type Pin No. Mnemonic Function Value
INPUTS 79 R
77 R
74 G
71 G
68 BB
66 BB
AIN0
AIN1
AIN0
AIN1
AIN0
AIN1
Analog Input for Converter R Channel 0 0.0 V to 1.0 V
Analog Input for Converter R Channel 1 0.0 V to 1.0 V
Analog Input for Converter G Channel 0 0.0 V to 1.0 V
Analog Input for Converter G Channel 1 0.0 V to 1.0 V
Analog Input for Converter B Channel 0 0.0 V to 1.0 V
Analog Input for Converter B Channel 1 0.0 V to 1.0 V
64 HSYNC0 Horizontal SYNC Input for Channel 0 3.3 V CMOS
63 HSYNC1 Horizontal SYNC Input for Channel 1 3.3 V CMOS
61 VSYNC0 Vertical SYNC Input for Channel 0 3.3 V CMOS
60 VSYNC1 Vertical SYNC Input for Channel 1 3.3 V CMOS
73 SOGIN0 Input for Sync-on-Green Channel 0 0.0 V to 1.0 V
70 SOGIN1 Input for Sync-on-Green Channel 1 0.0 V to 1.0 V
62 EXTCLK External Clock Input—Shares Pin with COAST 3.3 V CMOS
62 COAST PLL COAST Signal Input—Shares Pin with EXTCLK 3.3 V CMOS
81 PWRDN Power-Down Control 3.3 V CMOS
Rev. 0 | Page 7 of 64
AD9880
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Pin Type Pin No. Mnemonic Function Value
OUTPUTS 92 to 99 RED [7:0] Outputs of Red Converter, Bit 7 is MSB V
2 to 9 GREEN [7:0] Outputs of Green Converter, Bit 7 is MSB V
12 to 19 BLUE [7:0] Outputs of Blue Converter, Bit 7 is MSB V
89 DATACK Data Output Clock V
87 HSOUT HSYNC Output Clock (Phase-Aligned with DATACK) V
85 VSOUT VSYNC Output Clock (Phase-Aligned with DATACK) V
86 SOGOUT SOG Slicer Output V
84 O/E FIELD Odd/Even Field Output V
REFERENCES 57 FILT Connection For External Filter Components For PLL
POWER SUPPLY
80, 76, 72,
V
D
Analog Power Supply and DVI Terminators 3.3 V
67, 45, 33
100, 90, 10 V
59, 56, 54 PV
48, 32, 30 DV
DD
DD
DD
Output Power Supply 1.8 V to 3.3 V
PLL Power Supply 1.8 V
Digital Logic Power Supply 1.8 V
GND Ground 0 V
CONTROL 83 SDA Serial Port Data I/O 3.3 V CMOS
82 SCL Serial Port Data Clock 3.3 V CMOS
HDCP 49 DDC_SCL HDCP Slave Serial Port Data Clock 3.3 V CMOS
50 DDC_SDA HDCP Slave Serial Port Data I/O 3.3 V CMOS
51 MCL HDCP Master Serial Port Data Clock 3.3 V CMOS
52 MDA HDCP Master Serial Port Data I/O 3.3 V CMOS
AUDIO DATA OUTPUTS 28 S/PDIF S/PDIF Digital Audio Output V
27 I2S0 I2S Audio (Channels 1, 2) V
26 I2S1 I2S Audio (Channels 3, 4) V
25 I2S2 I2S Audio (Channels 5, 6) V
24 I2S3 I2S Audio (Channels 7, 8) V
20 MCLKIN External Reference Audio Clock In V
21 MCLKOUT Audio Master Clock Output V
22 SCLK Audio Serial Clock Output V
23 LRCLK Data Output Clock For Left And Right Audio Channels V
DIGITAL VIDEO DATA 35 Rx0+ Digital Input Channel 0 True TMDS
34 Rx0− Digital Input Channel 0 Complement TMDS
38 Rx1+ Digital Input Channel 1 True TMDS
37 Rx1− Digital Input Channel 1 Complement TMDS
41 Rx2+ Digital Input Channel 2 True TMDS
40 Rx2− Digital Input Channel 2 Complement TMDS
DIGITAL VIDEO CLOCK INPUTS 43 RxC+ Digital Data Clock True TMDS
44 RxC− Digital Data Clock Complement TMDS
DATA ENABLE 88 DE Data Enable 3.3 V CMOS
RTERM 46 RTERM Sets Internal Termination Resistance
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
500Ω
Rev. 0 | Page 8 of 64
AD9880
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Table 5. Pin Function Descriptions
Pin Description
INPUTS
R
AIN0
G
AIN0
BB
AIN0
R
AIN1
G
AIN1
BB
AIN1
Rx0+ Digital Input Channel 0 True.
Rx0− Digital Input Channel 0 Complement.
Rx1+ Digital Input Channel 1 True.
Rx1− Digital Input Channel 1 Complement.
Rx2+ Digital Input Channel 2 True.
Rx2−
RxC+ Digital Data Clock True.
RxC−
HSYNC0 Horizontal Sync Input Channel 0.
HSYNC1
VSYNC0 Vertical Sync Input Channel 0.
VSYNC1
SOGIN0 Sync-On-Green Input Channel 0.
SOGIN1
EXTCLK/COAST
EXTCLK/COAST External Clock.
Analog Input for the Red Channel 0.
Analog Input for the Green Channel 0.
Analog Input for the Blue Channel 0.
Analog Input for the Red Channel 1.
Analog Input for the Green Channel 1.
Analog Input for Blue Channel 1.
High impedance inputs that accept the red, green, and blue channel graphics signals, respectively. The three channels
are identical, and can be used for any colors, but colors are assigned for convenient reference. They accommodate
input signals ranging from 0.5 V to 1.0 V full scale. Signals should be ac-coupled to these pins to support clamp
operation. (see Figure 3 for an input reference circuit).
Digital input Channel 2 Complement.
These six pi
from a digital graphics transmitter.
Digital Data Clock Complement.
This cloc
Horizontal Sync Input Channel 1.
These inputs r
reference for pixel clock generation. The logic sense of this pin is controlled by serial register 0x12 Bits 5:4 (Hsync
polarity). Only the leading edge of Hsync is active; the trailing edge is ignored. When Hsync Polarity = 0, the falling
edge of Hsync is used. When Hsync Polarity = 1, the rising edge is active. The input includes a Schmitt trigger for noise
immunity.
Vertical Sync Input Channel 1.
These ar
Sync-On-Green Input Channel 1.
These inputs ar
pin is connected to a high speed comparator with an internally generated threshold. The threshold level can be
programmed in 10 mV steps to any voltage between 10 mV and 330 mV above the negative peak of the input signal.
The default voltage threshold is 150 mV. When connected to an ac-coupled graphics signal with embedded sync, it
produces a noninverting digital output on SOGOUT. (This is usually a composite sync signal, containing both vertical
and horizontal sync (Hsync) information that must be separated before passing the horizontal sync signal to Hsync.)
When not used, this input should be left unconnected. For more details on this function and how it should be
configured, refer to the
Coast Input to Clock Generator (Optional).
his input may be used to cause the pixel clock generator to stop synchronizing with Hsync and continue producing a
T
clock at its current frequency and phase. This is useful when processing signals from sources that fail to produce
horizontal sync pulses during the vertical interval. The Coast signal is generally not required for PC-generated signals.
The logic sense of this pin is controlled by Coast polarity (Register 0x18, Bits 6:5). When not used, this pin may be
grounded and input Coast polarity programmed to 1 (Register 0x18, Pin 5), or tied high (to V
and input Coast polarity programmed to 0. Input Coast polarity defaults to 1 at power-up. This pin is shared with the
EXTCLK function, which does not affect Coast functionality. For more details on Coast, see the description in the
neration section.
Ge
This allows the insertion of an external clock sour
shared with the Coast function, which will not affect EXTCLK functionality.
ns receive three pairs TMDS (Transition Minimized Differential Signaling) pixel data (at 10X the pixel rate)
k pair receives a TMDS clock at 1× pixel data rate.
eceive a logic signal that establishes the horizontal timing reference and provides the frequency
e the inputs for vertical sync.
e provided to assist with processing signals with embedded sync, typically on the green channel. The
Hsync and Vsync Inputs section.
through a 10 KΩ resistor)
D
ce rather than the internally generated PLL locked clock. This pin is
Clock
Rev. 0 | Page 9 of 64
AD9880
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Pin Description
PWRDN
FILT External Filter Connection.
OUTPUTS
HSOUT
VSOUT
SOGOUT
O/E FIELD
SERIAL PORT
SDA Serial Port Data I/O for programming AD9880 registers – I2C address is 0x98.
SCL Serial Port Data Clock for programming AD9880 registers.
DDCSDA Serial Port Data I/O for HDCP communications to transmitter – I2C address is 0x74 or 0x76.
DDCSCL Serial Port Data Clock for HDCP communications to transmitter.
MDA Serial Port Data I/O to EEPROM with HDCP keys – I2C address is 0xA0
MCL Serial Port Data Clock to EEPROM with HDCP keys.
DATA OUTPUTS
Red [7:0] Data Output, Red Channel.
Green [7:0] Data Output, Green Channel.
Blue [7:0]
DATA CLOCK
OUTPUT
DATACK
Power-Down Control/Three-State Control.
The func
For proper operation, the pixel clock generator PLL requires an ex
this pin. F
PCB Layout Recommendations.
Horizontal Sync Output.
A r
programmed via serial bus registers. By maintaining alignment with DATACK and Data, data timing with respect to
horizontal sync can always be determined.
Vertical Sync Output.
The separa
can be controlled via serial bus bit (Register 0x24 [6]).
Sync-On-Green Slicer Output.
This pin outputs one of f
Hsync from the filter, or the filtered Hsync. See the Sync processing block diagram (see Figure 8) to view how this pin is
c
performed via the sync separator.
Odd/Even Field Bit for Interlaced Video. This output will identify whether the cur
or even. The polarity of this signal is programmable via Register 0x24[4].
Data Output, Blue Channel. The main data outputs
fixed, but will be different if the color space converter is used. When the sampling time is changed by adjusting the
phase register, the output timing is shifted as well. The DATACK and HSOUT outputs are also moved, so the timing
relationship among the signals is maintained.
Data Clock Output.
T
clocks can be selected with Register 0x25 [7:6]. These are related to the pixel clock (1/2× pixel clock, 1× pixel clock, 2×
frequency pixel clock and a 90° phase shifted pixel clock) and they are produced either by the internal PLL clock
generator or EXTCLK and are synchronous with the pixel sampling clock. The polarity of DATACK can also be inverted
via Register 0x24 [0]. The sampling time of the internal pixel clock can be changed by adjusting the phase register.
When this is changed, the pixel-related DATACK timing is shifted as well. The DATA, DATACK, and HSOUT outputs are all
moved, so the timing relationship among the signals is maintained.
tion of this pin is programmable via Register 0x26 [2:1].
ternal filter. Connect the filter shown in Figure 6 to
or optimal performance, minimize noise and parasitics on this node. For more information see the section on
econstructed and phase-aligned version of the Hsync input. Both the polarity and duration of this output can be
ted Vsync from a composite signal or a direct pass through of the Vsync signal. The polarity of this output
our possible signals (controlled by Register 0x1D [1:0]): raw SOG, raw Hsync, regenerated
onnected. (Note: besides slicing off SOG, the output from this pin is not processed on the AD9880. Vsync separation is
rent field (in an interlaced signal) is odd
. Bit 7 is the MSB. The delay from pixel sampling time to output is
his is the main clock output signal used to strobe the output data and HSOUT into external logic. Four possible output
Rev. 0 | Page 10 of 64
AD9880
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Pin Description
POWER SUPPLY1
VD (3.3 V)
VDD (1.8 V – 3.3 V)
PVDD (1.8 V)
DVDD (1.8 V)
GND
1
The supplies should be sequenced such that VD and VDD are never less than 300 mV below DVDD. At no time should DVDD be more than 300 mV greater than VD or
VDD.
Analog Power Supply.
These pins
Digital Output Power Supply.
A large number of output pins (up to 27) switching at high speed (up to 150 MHz) generates many power supply
transients (noise). These supply pins are identified separately from the VD pins so special care can be taken to minimize
output noise transferred into the sensitive analog circuitry. If the AD9880 is interfacing with lower voltage logic, V
may be connected to a lower supply voltage (as low as 1.8 V) for compatibility.
Clock Generator Power Supply.
The most sensiti
and help the user design for optimal performance. The designer should provide quiet, noise-free power to these pins.
Digital Input Power Supply.
This sup
Ground.
The g
plane, with careful attention to ground current paths.
supply power to the ADCs and terminators. They should be as quiet and filtered as possible.
DD
ve portion of the AD9880 is the clock generation circuitry. These pins provide power to the clock PLL
plies power to the digital logic.
round return for all circuitry on chip. It is recommended that the AD9880 be assembled on a single solid ground
Rev. 0 | Page 11 of 64
AD9880
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DESIGN GUIDE
GENERAL DESCRIPTION
The AD9880 is a fully integrated solution for capturing analog
RGB or YUV signals and digitizing them for display on flat
panel monitors, projectors, or PDPs. In addition, the AD9880
has a digital interface for receiving DVI/HDMI signals and
is capable of decoding HDCP encrypted signals through connections to an internal EEPROM. The circuit is ideal for
providing an interface for HDTV monitors or as the front end
to high performance video scan converters.
Implemented in a high-performance CMOS process, the
in
terface can capture signals with pixel rates of up to 150 MHz.
The AD9880 includes all necessary input buffering, signal dc
r
estoration (clamping), offset and gain (brightness and contrast)
adjustment, pixel clock generation, sampling phase control, and
output data formatting. Included in the output formatting is a
color space converter (CSC), which accommodates any input
color space and can output any color space. All controls are
programmable via a 2-wire serial interface. Full integration of
these sensitive analog functions makes system design straightforward and less sensitive to the physical and electrical
environment.
DIGITAL INPUTS
All digital control inputs (Hsync, Vsync, I2C) on the AD9880
operate to 3.3 V CMOS levels. In addition, all digital inputs
except the TMDS (HDMI/DVI) inputs are 5 V tolerant.
(Applying 5 V to them does not cause any damage.) TMDS
inputs (RX0+/–, RX1+/–, RX2+/–, and RXC+/–) must maintain
a 100 Ω differential impedance (through proper PCB layout)
from the connector to the input where they are internally
terminated (50 Ω to 3.3 V). If additional ESD protection is
desired, use of a California Micro Devices (CMD) CM1213
(among others) series low capacitance ESD protection offers 8
kV of protection to the HDMI TMDS lines.
In an ideal world of perfectly matched impedances, the best
rformance can be obtained with the widest possible signal
pe
bandwidth. The ultrawide bandwidth inputs of the AD9880
(330 MHz) can track the input signal continuously as it moves
from one pixel level to the next, and digitizes the pixel during a
long, flat pixel time. In many systems, however, there are
mismatches, reflections, and noise, which can result in excessive
ringing and distortion of the input waveform. This makes it
more difficult to establish a sampling phase that provides good
image quality. It has been shown that a small inductor in series
with the input is effective in rolling off the input bandwidth
slightly, and providing a high quality signal over a wider range
of conditions. Using a Fair-Rite #2508051217Z0 High Speed
Signal Chip Bead inductor in the circuit shown in
od results in most applications.
go
RGB
INPUT
Figure 3. Analog Input Interface Circuit
47nF
75Ω
Figure 3 gives
R
AIN
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AIN
B
AIN
05087-003
HSYNC AND VSYNC INPUTS
The interface also takes a horizontal sync signal, which is used
to generate the pixel clock and clamp timing. This can be either
a sync signal directly from the graphics source, or a preprocessed TTL or CMOS level signal.
The Hsync input includes a Schmitt trigger buffer for immunity
t
o noise and signals with long rise times. In typical PC-based
graphic systems, the sync signals are simply TTL-level drivers
feeding unshielded wires in the monitor cable. As such, no
termination is required.
SERIAL CONTROL PORT
The serial control port is designed for 3.3 V logic. However, it is
tolerant of 5 V logic signals.
ANALOG INPUT SIGNAL HANDLING
The AD9880 has six high-impedance analog input pins for the
red, green, and blue channels. They accommodate signals
ranging from 0.5 V to 1.0 V p-p.
Signals are typically brought onto the interface board via a
VI-I connector, a 15-pin D connector, or RCA-type
D
connectors. The AD9880 should be located as close as practical
to the input connector. Signals should be routed via 75
matched impedance traces to the IC input pins.
At that point the signal should be resistively terminated (75
o the signal ground return) and capacitively coupled to the
t
AD9880 inputs through 47 nF capacitors. These capacitors form
part of the dc restoration circuit.
Rev. 0 | Page 12 of 64
OUTPUT SIGNAL HANDLING
The digital outputs are designed to operate from 1.8 V to 3.3 V
(V
).
DD
CLAMPING
RGB Clamping
To properly digitize the incoming signal, the dc offset of the
input must be adjusted to fit the range of the on-board ADC.
Most graphics systems produce RGB signals with black at
g
round and white at approximately 0.75 V. However, if sync
signals are embedded in the graphics, the sync tip is often at
ground and black is at 300 mV. Then white is at approximately
1.0 V. Some common RGB line amplifier boxes use emitterfollower buffers to split signals and increase drive capability.
AD9880
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This introduces a 700 mV dc offset to the signal, which must be
removed for proper capture by the AD9880.
within ½ LSB in 10 lines with a clamp duration of 20 pixel
periods on a 75 Hz SXGA signal.
The key to clamping is to identify a portion (time) of the signal
hen the graphic system is known to be producing black. An
w
offset is then introduced which results in the ADCs producing a
black output (Code 0x00) when the known black input is
present. The offset then remains in place when other signal
levels are processed, and the entire signal is shifted to eliminate
offset errors.
In most pc graphics systems, black is transmitted between active
ideo lines. With CRT displays, when the electron beam has
v
completed writing a horizontal line on the screen (at the right
side), the beam is deflected quickly to the left side of the screen
(called horizontal retrace) and a black signal is provided to
prevent the beam from disturbing the image.
In systems with embedded sync, a blacker-than-black signal
(H
sync) is produced briefly to signal the CRT that it is time to
begin a retrace. For obvious reasons, it is important to avoid
clamping on the tip of Hsync. Fortunately, there is virtually
always a period following Hsync called the back porch where a
good black reference is provided. This is the time when
clamping should be done.
Clamp timing employs the AD9880 internal clamp timing
enerator. The clamp placement register is programmed with
g
the number of pixel periods that should pass after the trailing
edge of Hsync before clamping starts. A second register (clamp
duration) sets the duration of the clamp. These are both 8-bit
values, providing considerable flexibility in clamp generation.
The clamp timing is referenced to the trailing edge of Hsync
because, though Hsync duration can vary widely, the back
porch (black reference) always follows Hsync. A good starting
point for establishing clamping is to set the clamp placement to
0x08 (providing 8 pixel periods for the graphics signal to
stabilize after sync) and set the clamp duration to 0x14 (giving
the clamp 20 pixel periods to reestablish the black reference).
For three-level syncs embedded on the green channel, it is
necessary to increase the clamp placement to beyond the positive portion of the sync. For example, a good clamp placement
(Register 0x19) for a 720p input is 0x26. This delays the start of
clamp by 38 pixel clock cycles after the rising edge of the threelevel sync, allowing plenty of time for the signal to return to a
black reference.
YUV Clamping
YUV graphic signals are slightly different from RGB signals in
that the dc reference level (black level in RGB signals) can be
at the midpoint of the graphics signal rather than the bottom.
For these signals it can be necessary to clamp to the midscale
range of the ADC range (128) rather than bottom of the ADC
range (0).
Clamping to midscale rather than ground can be accomplished
b
y setting the clamp select bits in the serial bus register. Each of
the three converters has its own selection bit so that they can be
clamped to either midscale or ground independently. These bits
are located in Register 0x1B [7:5]. The midscale reference
voltage is internally generated for each converter.
Auto Offset
The auto-offset circuit works by calculating the required offset
setting to yield a given output code during clamp. When this
block is enabled, the offset setting in the I
clamp code rather than an actual offset. The circuit compares
the output code during clamp to the desired code and adjusts
the offset up or down to compensate.
The offset on the AD9880 can be adjusted automatically to a
s
pecified target code. Using this option allows the user to set the
offset to any value and be assured that all channels with the
same value programmed into the target code will match. This
eliminates any need to adjust the offset at the factory. This
function is capable of running continuously anytime the clamp
is asserted.
There is an offset adjust register for each channel, namely the
ffset registers at Addresses 0x08, 0x0A, and 0x0C. The offset
o
adjustment is a signed (twos complement) number with
±64 LSB range. The offset adjustment is added to whatever
offset the auto-offset comes up with. For example: using ground
clamp, the target code is set to 4. To get this code, the autooffset generates an offset of 68. If the offset adjustment is set to
10, the offset sent to the converter is 78. Likewise, if the offset
adjust is set to –10, the offset sent to the converter is 58. Refer to
application note AN-775, Implementing the Auto-Offset
Function of the AD9880, for a detailed description of how to
use this function.
2
C is seen as a desired
Clamping is accomplished by placing an appropriate charge on
t
he external input coupling capacitor. The value of this capacitor affects the performance of the clamp. If it is too small,
there is a significant amplitude change during a horizontal line
time (between clamping intervals). If the capacitor is too large,
then it takes excessively long for the clamp to recover from a
large change in incoming signal offset. The recommended value
(47 nF) results in recovering from a step error of 100 mV to
Rev. 0 | Page 13 of 64
Sync-on-Green (SOG)
The SOG input operates in two steps. First, it sets a baseline
clamp level off of the incoming video signal with a negative
peak detector. Second, it sets the sync trigger level to a
programmable level (typically 150 mV) above the negative
peak. The SOG input must be ac-coupled to the green analog
input through its own capacitor. The value of the capacitor must
be 1 nF ± 20%. If SOG is not used, this connection is not
AD9880
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required. Note that the SOG signal is always negative polarity.
For additional detail on setting the SOG threshold and other
SOG-related functions, see the
47nF
47nF
47nF
1nF
Figure 4. Typical Clamp Configuration for RGB/YUV Applications
Clock Generation
A PLL is employed to generate the pixel clock. In this PLL,
the Hsync input provides a reference frequency. A voltage
controlled oscillator (VCO) generates a much higher pixel clock
frequency. This pixel clock is divided by the PLL divide value
(Registers 0x01 and 0x02) and phase compared with the Hsync
input. Any error is used to shift the VCO frequency and
maintain lock between the two signals.
The stability of this clock is a very important element in provi-
g the clearest and most stable image. During each pixel time,
din
there is a period during which the signal slews from the old
pixel amplitude and settles at its new value. This is followed by a
time when the input voltage is stable before the signal must slew
to a new value. The ratio of the slewing time to the stable time is
a function of the bandwidth of the graphics DAC and the
bandwidth of the transmission system (cable and termination).
It is also a function of the overall pixel rate. Clearly, if the
dynamic characteristics of the system remain fixed, then the
slewing and settling time is likewise fixed. This time must be
subtracted from the total pixel period, leaving the stable period.
At higher pixel frequencies, the total cycle time is shorter and
the stable pixel time also becomes shorter.
PIXEL CLOCKINVALID SAMPLE TIMES
Sync Processing section.
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SOG
05087-004
The PLL characteristics are determined by the loop filter design,
he PLL charge pump current, and the VCO range setting. The
t
loop filter design is illustrated in Figure 6. Recommended sett
ings of the VCO range and charge pump current for VESA
standard display modes are listed in
C
P
8nF
R
1.5kΩ
FILT
Figure 6. PLL Loop Filter Detail
Tabl e 8.
PV
C
Z
80nF
Z
D
05087-006
Four programmable registers are provided to optimize the
performance of the PLL. These registers are
•The 12-Bi
t Divisor Register. The input Hsync frequency
range can be any frequency which, combined with the
PLL_Div, does not exceed the VCO range . The PLL multiplies the frequency of the Hsync signal, producing pixel
clock frequencies in the range of 10 MHz to 100 MHz. The
divisor register controls the exact multiplication factor.
•The 2-Bi
t VCO Range Register. To improve the noise
performance of the AD9880, the VCO operating frequency
range is divided into four overlapping regions. The VCO
range register sets this operating range. The frequency
ranges for the lowest and highest regions are shown in
Tabl e 6.
• Table 6.
VCORNGE Pixel Rate Range
00 12-30
01 30-60
10 60-120
11 120-150
•The 5-Bit Phase Adjust Register. The phase of the
generated sampling clock can be shifted to locate an
optimum sampling point within a clock cycle. The phase
adjust register provides 32 phase-shift steps of 11.25° each.
The Hsync signal with an identical phase shift is available
through the HSOUT pin.
05087-005
Figure 5. Pixel Sampling Times
Any jitter in the clock reduces the precision with which the
sampling time can be determined and must also be subtracted
from the stable pixel time. Considerable care has been taken in
the design of the AD9880’s clock generation circuit to minimize
jitter. The clock jitter of the AD9880 is less than 13% of the total
pixel time in all operating modes, making the reduction in the
valid sampling time due to jitter negligible.
Rev. 0 | Page 14 of 64
The COAST pin or the internal Coast is used to allow the PLL
t
o continue to run at the same frequency, in the absence of the
incoming Hsync signal or during disturbances in Hsync (such
as equalization pulses). This can be used during the vertical
sync period or any other time that the Hsync signal is unavailable. The polarity of the Coast signal can be set through the
Coast polarity register. Also, the polarity of the Hsync signal
can be set through the Hsync polarity register. For both Hsync
and Coast, a value of 1 is active high. The internal Coast
function is driven off the Vsync signal, which is typically a time
when Hsync signals can be disrupted with extra equalization
pulses.
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Power Management
The AD9880 uses the activity detect circuits, the active interface
bits in the serial bus, the active interface override bits, the
power-down bit, and the power-down pin to determine the
correct power state. There are four power states: full-power,
seek mode, auto power-down and power-down.
Tabl e 7 s
ummarizes how the AD9880 determines which power
mode to be in and which circuitry is powered on/off in each of
these modes. The power-down command has priority and then
Table 7. Power-Down Mode Descriptions
Inputs
Mode Power-Down
1
Sync Detect
2
Auto PD Enable
Full Power 1 1 X Everything
Seek Mode 1 0 0 Everything
Seek Mode 1 0 1
Power-Down 0 X
1
Power-down is controlled via Bit 0 in Serial Bus Register 0x26.
2
Sync detect is determined by OR’ing Bits 7 to 2 in Serial Bus Register 0x15.
3
Auto power-down is controlled via Bit 7 in Serial Bus Register 0x27
Table 8. Recommended VCO Range and Charge Pump Current Settings for Standard Display Formats
Standard Resolution Refresh Rate Horizontal Frequency Pixel Rate VCO Range
These are preliminary recommendations for the analog PLL and are subject to change without notice.
the automatic circuitry. The power-down pin (Pin 81—polarity
set by Register 0x26[3]) can drive the chip into four powerdown options. Bits 2 and 1 of Register 0x26 control these four
options. Bit 0 controls whether the chip is powered down or the
outputs are placed in high impedance mode (with the exception
of SOG). Bits 7 to 4 of Register 0x26 control whether the
outputs, SOG, Sony Philips digital interface (SPDIF ) or I2S (IIS
or Inter IC sound bus) outputs are in high impedance mode or
not. See the 2-Wire Serial Control Register Detail section for
the details.
3
Power-On or Comments
Serial bus, sync activity detect, SOG, band gap
ference
re
Serial bus, sync activity detect, SOG, band gap
ference
re
1
Current
Rev. 0 | Page 15 of 64
AD9880
K
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TIMING
The output data clock signal is created so that its rising edge
always occurs between data transitions and can be used to latch
the output data externally.
There is a pipeline in the AD9880, which must be flushed
efore valid data becomes available. This means 23 data sets are
b
presented before valid data is available.
The timing diagram in Fi
AD9880.
DATAC
gure 7 shows the operation of the
t
PER
t
DCYCLE
clock generator during Vsync, it is important to ignore these
distortions. If the pixel clock PLL sees extraneous pulses, it
attempts to lock to this new frequency, and changes frequency
by the end of the Vsync period. It then takes a few lines of
correct Hsync timing to recover at the beginning of a new
frame, resulting in a tearing of the image at the top of the
display.
The Coast input is provided to eliminate this problem. It is an
nchronous input that disables the PLL input and allows the
asy
clock to free run at its then-current frequency. The PLL can free
run for several lines without significant frequency drift.
Coast can be generated internally by the AD9880 (see
ister 0x12 [1]), can be driven directly from a Vsync input,
Reg
or can be provided externally by the graphics controller.
t
SKEW
DATA
HSOUT
05087-007
Figure 7. Output Timing
Hsync Timing
Horizontal Sync (Hsync) is processed in the AD9880 to
eliminate ambiguity in the timing of the leading edge with
respect to the phase-delayed pixel clock and data.
The Hsync input is used as a reference to generate the pixel
mpling clock. The sampling phase can be adjusted, with
sa
respect to Hsync, through a full 360° in 32 steps via the phase
adjust register (to optimize the pixel sampling time). Display
systems use Hsync to align memory and display write cycles, so
it is important to have a stable timing relationship between the
Hsync output (HSOUT) and data clock (DATACK).
Three things happen to Hsync in the AD9880. First, the polarity
f Hsync input is determined and thus has a known output
o
polarity. The known output polarity can be programmed either
active high or active low (Register 0x24, Bit 7). Second, HSOUT
is aligned with DATACK and data outputs. Third, the duration
of HSOUT (in pixel clocks) is set via Register 0x23. HSOUT is
the sync signal that should be used to drive the rest of the
display system.
Coast Timing
In most computer systems, the Hsync signal is provided
continuously on a dedicated wire. In these systems, the Coast
input and function are unnecessary, and should not be used and
the pin should be permanently connected to the inactive state.
Sync Processing
The inputs of the sync processing section of the AD9880 are
combinations of digital Hsyncs and Vsyncs, analog sync-ongreen, or sync-on-Y signals, and an optional external Coast
signal. From these signals it generates a precise, jitter-free (9%
or less at 95 MHz) clock from its PLL; an odd-/even-field signal;
Hsync and Vsync out signals; a count of Hsyncs per Vsync; and
a programmable SOG output. The main sync processing blocks
are the sync slicer, sync separator, Hsync filter, Hsync regenerator, Vsync filter, and Coast generator.
The sync slicer extracts the sync signal from the green graphics
r luminance video signal that is connected to the SOGIN input
o
and outputs a digital composite sync. The sync separator’s task
is to extract Vsync from the composite sync signal, which can
come from either the sync slicer or the Hsync input. The Hsync
filter is used to eliminate any extraneous pulses from the Hsync
or SOGIN inputs, outputting a clean, low-jitter signal that is
appropriate for mode detection and clock generation. The
Hsync regenerator is used to recreate a clean, although not low
jitter, Hsync signal that can be used for mode detection and
counting Hsyncs per Vsync. The Vsync filter is used to eliminate spurious Vsyncs, maintain a stable timing relationship
between the Vsync and Hsync output signals, and generate the
odd/even field output. The Coast generator creates a robust
Coast signal that allows the PLL to maintain its frequency in
the absence of Hsync pulses.
In some systems, however, Hsync is disturbed during the vertical sy
nc period (Vsync). In some cases, Hsync pulses disappear.
In other systems, such as those that employ composite sync
(Csync) signals or embedded SOG, Hsync includes equalization
pulses or other distortions during Vsync. To avoid upsetting the
Rev. 0 | Page 16 of 64
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Sync Slicer
The purpose of the sync slicer is to extract the sync signal from
the green graphics or luminance video signal that is connected
to the SOGIN input. The sync signal is extracted in a two step
process. First, the SOG input (typically 0.3 V below the black
level) is detected and clamped to a known dc voltage. Next, the
signal is routed to a comparator with a variable trigger level (set
by Register 0x1D, Bits [7:3]), but nominally 0.128 V above the
clamped voltage. The sync slicer output is a digital composite
sync signal containing both Hsync and Vsync information (see
Figure 9).
HSYNC 0
HSYNC 1
SOGIN 0
SOGIN 1
VSYNC 0
VSYNC 1
COAST
1
AD
1
AD
SYNC
SLICER
SYNC
SLICER
1
AD
1
AD
AD9880
1
ACTIVITY DETECT
2
POLARITY DETECT
3
REGENERATED HSYNC
4
FILTERED HSYNC
5
SET POLARITY
PD
PD
AD
AD
PD
PD
CHANNEL
SELECT
MUX
2
2
MUX
1
1
MUX
2
2
FILTER COAST VSYNC
VSYNC
0x12:0
[0x11:3]
PROCESSOR
VSYNC FILTER
SYNC
AND
HSYNC
SELECT
MUX
PLL SYNC FILTER EN
MUX
COAST SELECT
0x12:1
SP SYNC FILTER EN
0x21:6
COAST
Figure 8. Sync Processing Block Diagram
[0x11:7]
0x21:7
MUX
HSYNC
4
FH
MUX
PLL CLOCK
GENERATOR
HSYNC FILTER
AND
REGENERATOR
RH
SOGOUT SELECT
FILTERED
HSYNC/VSYNC
COUNTER
REG 26H, 27H
3
MUX
0x24:2,1
VSYNC
VSYNC
5
SP
MUX
VSYNC FILTER EN
0x21:5
5
SP
5
SP
5
SP
SOG OUT
VSYNC OUT
ODD/EVEN
FIELD
HSYNC OUT
DATACK
05087-008
NEGATIVE PULSE WIDTH = 40 SAMPLE CLOCKS
700mV MAXIMUM
SOG INPUT
SOGOUT OUTPUT
CONNECTED TO
HSYNCIN
COMPOSITE
SYNC
AT HSYNCIN
VSYNCOUT
FROM SYNC
SEPARATOR
–300mV
0mV
–300mV
Figure 9. Sync Slicer and Sync Separator Output
Rev. 0 | Page 17 of 64
04740-015
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Sync Separator
As part of sync processing, the sync separator’s task is to extract
Vsync from the composite sync signal. It works on the idea that
the Vsync signal stays active for a much longer time than the
Hsync signal. By using a digital low-pass filter and a digital
comparator, it rejects pulses with small durations (such as
Hsyncs and equalization pulses) and only passes pulses with
large durations, such as Vsync (see Figure 9).
The threshold of the digital comparator is programmable for
max
imum flexibility. To program the threshold duration, write
a value (N) to Register 0x11. The resulting pulse width is
N × 200 ns. So, if N = 5 the digital comparator threshold is 1 µs.
Any pulses less than 1 µs is rejected, while any pulse greater
than 1 µs passes through.
The sync separator on the AD9880 is simply an 8-bit digital
co
unter with a 6 MHz clock. It works independently of the
polarity of the composite sync signal. Polarities are determined
elsewhere on the chip. The basic idea is that the counter counts
up when Hsync pulses are present. But since Hsync pulses are
relatively short in width, the counter only reaches a value of N
before the pulse ends. It then starts counting down until
eventually reaching 0 before the next Hsync pulse arrives. The
specific value of N varies for different video modes, but is
always less than 255. For example with a 1 s width Hsync, the
counter only reaches 5 (1 s/200 ns = 5). Now, when Vsync is
present on the composite sync the counter also counts up.
However, since the Vsync signal is much longer, it counts to a
higher number, M. For most video modes, M is at least 255.
So, Vsync can be detected on the composite sync signal by
detecting when the counter counts to higher than N. The
specific count that triggers detection, T, can be programmed
through the Serial Register 0x11.
Once Vsync has been detected, there is a similar process to
ct when it goes inactive. At detection, the counter first
dete
resets to 0, then starts counting up when Vsync finishes.
Similarly to the previous case, it detects the absence of Vsync
when the counter reaches the threshold count, T. In this way, it
rejects noise and/or serration pulses. Once Vsync is detected to
be absent, the counter resets to 0 and begins the cycle again.
There are two things to keep in mind when using the sync
eparator. First, the resulting clean Vsync output is delayed
s
from the original Vsync by a duration equal to the digital
comparator threshold (N × 200 ns). Second, there is some
variability to the 200 ns multiplier value. The maximum variability over all operating conditions is ±20% (160 ns to 240 ns).
Since normal Vsync and Hsync pulse widths differ by a factor of
about 500 or more, 20% variability is not an issue.
Hsync Filter and Regenerator
The Hsync filter is used to eliminate any extraneous pulses from
the Hsync or SOGIN inputs, outputting a clean, low-jitter signal
that is appropriate for mode detection and clock generation.
The Hsync regenerator is used to recreate a clean, although not
low jitter, Hsync signal that can be used for mode detection and
counting Hsyncs per Vsync. The Hsync regenerator has a high
degree of tolerance to extraneous and missing pulses on the
Hsync input, but is not appropriate for use by the PLL in
creating the pixel clock because of jitter.
The Hsync regenerator runs automatically and requires no
etup to operate. The Hsync filter requires the setting up of a
s
filter window. The filter window sets a periodic window of time
around the regenerated Hsync leading edge where valid Hsyncs
are allowed to occur. The general idea is that extraneous pulses
on the sync input occur outside of this filter window and thus
are filtered out. To set the filter window timing, program a value
(x) into Register 0x20. The resulting filter window time is ±x
times 25 ns around the regenerated Hsync leading edge. Just
as for the sync separator threshold multiplier, allow a ±20%
variance in the 25 ns multiplier to account for all operating
conditions (20 ns to 30 ns range).
A second output from the Hsync filter is a status bit (Reg-
ter 0x16[0]) that tells whether extraneous pulses are present
is
on the incoming sync signal or not. Extraneous pulses are often
included for copy protection purposes; this status bit can be
used to detect that.
The filtered Hsync (rather than the raw Hsync/SOGIN signal)
or pixel clock generation by the PLL is controlled by
f
Register 0x21[6]. The regenerated Hsync (rather than the
raw Hsync/SOGIN signal) for sync processing is controlled by
Register 0x21[7]. Use of the filtered Hsync and regenerated
Hsync is recommended. See Figure 10 for an illustration of a
filtered Hsync.
Rev. 0 | Page 18 of 64
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HSYNCIN
FILTER
WINDOW
HSYNCOUT
VSYNC
Figure 10. Sync Processing Filter
Vsync Filter and Odd/Even Fields
The Vsync filter is used to eliminate spurious Vsyncs, maintain
a consistent timing relationship between the Vsync and Hsync
output signals, and generate the odd/even field output.
The filter works by examining the placement of Vsync with
spect to Hsync and, if necessary, slightly shifting it in time at
re
the VSOUT output. The goal is to keep the Vsync and Hsync
leading edges from switching at the same time, eliminating
confusion as to when the first line of a frame occurs. Enabling
the Vsync filter is done with Register 0x21[5]. Use of the Vsync
filter is recommended for all cases, including interlaced video,
and is required when using the Hsync per Vsync counter.
Figure 12 illustrates even/odd field determination in two
situations.
FILTER
WINDOW
QUADRANT
HSYNCIN
VSYNCIN
VSYNCOUT
O/E FIELD
QUADRANT
HSYNCIN
VSYNCIN
EQUALIZATION
PULSES
EXPECTED
EDGE
05087-010
SYNC SEPARATOR THRESHOLD
FIELD 1FIELD 0
23214431
EVEN FIELD
Figure 11.
SYNC SEPARATOR THRESHOLD
FIELD 1FIELD 0
23214431
FIELD 1FIELD 0
FIELD 1FIELD 0
05087-011
Rev. 0 | Page 19 of 64
VSYNCOUT
O/E FIELD
ODD FIELD
Figure 12. Vsync Filter—Odd/Even
05087-012
AD9880
www.BDTIC.com/ADI
HDMI RECEIVER
The HDMI receiver section of the AD9880 allows the reception
of a digital video stream, which is backward-compatible with
DVI and able to accommodate not only video of various formats (RGB, YCrCb 4:4:4, 4:2:2), but also up to eight channels of
audio. Infoframes are transmitted carrying information about
the video format, audio clocks, and many other items necessary
for a monitor to utilize fully the information stream available.
The earlier digital visual interface (DVI) format was restricted
an RGB 24 bit color space only. Embedded in this data
to
stream were Hsyncs, Vsyncs and display enable (DE) signals,
but no audio information. The HDMI specification allows
trans-mission of all the DVI capabilities, but adds several
YCrCb formats that make the inclusion of a programmable
color space converter (CSC) a very desirable feature. With this,
the scaler following the AD9880 can specify that it always
wishes to receive a particular format, for instance, 4:2:2 YCrCb
regardless of the transmitted mode. If RGB is sent, the CSC can
easily convert that to 4:2:2 YCrCb while relieving the scaler of
this task.
In addition, the HDMI specification supports the transmission
o
f up to eight channels of S/PDIF or I2S audio. The audio
information is packetized and transmitted during the video
blanking periods along with specific information about the
clock frequency. Part of this audio information (Audio
Infoframe) tells the user how many channels of audio, where
they should be placed, information regarding the source (make,
model), and other data.
DE GENERATOR
The AD9880 has an onboard generator for DE, for start of
active video (SAV), and for end of active video (EAV), all of
which are necessary for describing the complete data stream for
a BT656 compatible output. In addition to this particular
output, it is possible to generate the DE for cases in which a
scaler is not planned to be used. This signal alerts the following
circuitry as to which are displayable video pixels.
4:4:4 TO 4:2:2 FILTER
The AD9880 contains a filter which allows it to convert a signal
from YCrCb 4:4:4 to YCrCb 4:2:2 while maintaining the
maximum accuracy and fidelity of the original signal.
Input Color space to Output Color space
The AD9880 can accept a wide variety of input formats and
either retain that format or convert to another. Input formats
supported are
• 4:4:4 Y
• 4:2:2 Y
• RG
CrCb 8 bit
CrCb 8, 10, and 12 bit
B 8-bit
Output modes supported are
• 4:4:4 Y
• 4:2:2 Y
• Dual 4:2:2
CrCb 8 bits
CrCb 8, 10, and 12 bits
YCrCb 8 bits.
Color space Conversion (CSC) Matrix
The color space conversion (CSC) matrix in the AD9880
consists of three identical processing channels. In each channel,
three input values are multiplied by three separate coefficients.
Also included are an offset value for each row of the matrix and
a scaling multiple for all values. Each value has a 13 bit twos
complement resolution to ensure the signal integrity is maintained. The CSC is designed to run at speeds up to 150 MHz
supporting resolutions up to 1080 p at 60 Hz. With any-to-any
color space support, formats such as RGB, YUV, YCbCr, and
others are supported by the CSC.
The main inputs, Rin, Gin, and Bin come from the 8- to 12-bit
in
puts from each channel. These inputs are based on the input
format detailed in Ta b le 7 to Ta bl e 15. The mapping of these
inputs to the CSC inputs is shown in Tab l e 9.
Table 9. CSC Port Mapping
Input Channel CSC Input Channel
R/CR R
Gr/Y G
B/CB BB
IN
IN
IN
One of the three channels is represented in Figure 13. In each
processing channel the three inputs are multiplied by three
separate coefficients marked a1, a2, and a3. These coefficients
are divided by 4096 to obtain nominal values ranging from
–0.9998 to +0.9998. The variable labeled a4 is used as an offset
control. The CSC_mode setting is the same for all three
processing channels. This multiplies all coefficients and offsets
by a factor of 2
csc_mode
.
The functional diagram for a single channel of the CSC as
n Figure 13 is repeated for the remaining G and B
shown i
channels. The coefficients for these channels are b1, b2, b3, b4,
c1, c2, c3, and c4.
CSC_MODE[1:0]
+
a4[12:0]
+
×4
2
R
[11:0]
×2
OUT
1
0
a1[12:0]
[11:0]
R
IN
B
[11:0]
IN
G
[11:0]
IN
×
a2[12:0]
×
a3[12:0]
×
1
×
×
×
+
4096
1
4096
1
4096
Figure 13. Single CSC Channel
05087-013
Rev. 0 | Page 20 of 64
AD9880
O
www.BDTIC.com/ADI
A programming example and register settings for several
common conversions are listed in the Color Space Converter
(CSC) Common Settings.
•S
peaker placement
•N
and CTS values (for reconstruction of the audio)
For a detailed functional description and more programming
mples, please refer to the application note AN-795, AD9880
exa
Color space Converter User's Guide.
AUDIO PLL SETUP
Data contained in the Audio Infoframes among other registers
define for the AD9880 HDMI receiver not only the type of
audio, but the sample frequency. It also contains information
about the N and CTS values used to recreate the clock. With
this information it is possible to regenerate the audio sampling
frequency. The audio clock is regenerated by dividing the 20-bit
CTS value into the TMDS clock, then multiplying by the 20-bit
N value. This yields a multiple of the fs (sampling frequency) of
either 128 × fs or 256 × fs. It is possible for this to be specified
up to 1024 × fs.
SINK DEVICESOURCE DEVICE
1
128 ×
VIDEO
CLOCK
N
1
N AND CTS VALUES ARE TRANSMITTED USING THE
"AUDIO CLOCK REGENERATION" PACKET. VIDE
CLOCK IS TRANSMITTED ON TMDS CLOCK CHANNEL.
DIVIDE
f
S
BY
REGISTER
CYCLE
N
TIME
COUNTER
N
Figure 14. N and CTS for Audio Clock
CTS
TMDS
CLOCK
1
N
DIVIDE
BY
CTS
MUTIPLY
BY
N
128 ×
f
S
AUDIO BOARD LEVEL MUTING
The audio can be muted through the Infoframes or locally via
the serial bus registers. This can be controlled with
Register R0x57, Bits [7:4].
AVI Infoframes
Contained within the HDMI TMDS transmission are
Infoframes containing specific information for the monitor
such as
•A
udio information
o 2 to
o Au
8 channels of audio identified
dio coding
05087-014
• Mu
• S
ting
ource information
oCD
CD
o SA
o DV
• V
o V
o Co
o As
o H
o M
• V
oV
D
ideo information
ideo ID Code (per CEA861B)
lor space
pect ratio
orizontal and vertical bar information
PEG frame information (I, B, or P frame)
endor (transmitter source) information
endor name and product model
This information is the fundamental difference between DVI
nd HDMI transmissions and is located in read-only registers
a
R0x5A to R0xEE. In addition to this information, registers are
provided that indicate that new information has been received.
Registers with addresses ending in 0xX7 or 0xXF beginning at
R0x87 contain the new data flags (NDF) information. All of
these registers contain the same information and all are reset
once any of them are read. Although there is no external
interrupt signal, it is very straightforward for the user to read
any of these registers and see if there is new information to be
processed.
TIMING DIAGRAMS
The following timing diagrams show the operation of the
AD9880.The output data clock signal is created so that its rising
edge always occurs between data transitions and can be used to
latch the output data externally. There is a pipeline in the
AD9880, which must be flushed before valid data becomes
available. This means six data sets are presented before valid
data is available.
oA
udio sampling frequency
Rev. 0 | Page 21 of 64
AD9880
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DATAINP0P1P2P5
HSIN
DATACLK
DATAOUTP0P1P2
HSOUT
P3P4
2 CLOCK CYCLE DELAY
P9P6
P8P10P11P7
8 CLOCK CYCLE DELAY
Figure 15. RGB ADC Timing
P3
05087-015
DATAINP0P1P2P5
HSIN
DATACLK
YOUTY0Y1Y2
CB/CROUTB0R0B2
HSOUT
1. PIXEL AFTER HSOUT CORRESPONDS TO BLUE INPUT.
2. EVEN NUMBER OF PIXEL DELAY BETWEEN HSOUT AND DATAOUT.
P3P4
2 CLOCK CYCLE DELAY
Figure 16. YCrCb ADC Timing
P9P6
P8P10P11P7
8 CLOCK CYCLE DELAY
Y3
R2
05087-016
Table 10.
Port Red Green Blue
Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
G [3:0] DDR ↑ B [7:4] DDR ↑ B [3:0] DDR 4:2:2 ↑ CbCr [11:0]
DDR
↓ R [7:0] DDR ↓ G [7:4] DDR 4:2:2 ↓ Y,Y [11:0]
DDR
DDR 4:2:2
↑ CbCr ↓ Y, Y
4:2:2-12 CbCr [11:0] Y [11:0]
1
Arrows in the table indicate clock edge. Rising edge of clock = ↑, falling edge = ↓.
Rev. 0 | Page 22 of 64
AD9880
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2-WIRE SERIAL REGISTER MAP
The AD9880 is initialized and controlled by a set of registers that determines the operating modes. An external controller is employed to
write and read the control registers through the 2-wire serial interface port.
Table 11. Control Register Map
Hex
Address
0x00 Read [7:0] 00000000 Chip Revision Chip revision ID. Revision is read [7:4]. [3:0].
0x01 Read/Write [7:0] 01101001 PLL Divider MSB PLL feedback divider value MSB.
0x02 Read/Write [7:4] 1101**** PLL Divider PLL feedback divider value.
0x03 Read/Write [7:6] 01****** VCO Range VCO range.
[5:3] **001*** Charge Pump Charge pump current control for PLL.
[2] *****0** External Clock Enable
0x04 Read/Write [7:3] 10000*** Phase Adjust Selects the clock phase to use for the ADC clock.
0x05 Read/Write [7:0] 10000000 Red Gain
0x06 Read/Write [7:0] 10000000 Green Gain
0x07 Read/Write [7:0] 10000000 Blue Gain
0x08 Read/Write [7:0] 00000000 Red Offset Adjust User adjustment of auto offset. Allows user control of brightness.
0x09 Read/Write [7:0] 10000000 Red Offset Red offset/target code. 0 = small offset, 255 = large offset.
0x0A Read/Write [7:0] 00000000 Green Offset Adjust User adjustment of auto offset. Allows user control of brightness.
0x0B Read/Write [7:0] 10000000 Green Offset Green offset/target code. 0 = small offset, 255 = large offset.
0x0C Read/Write [7:0] 00000000 Blue Offset Adjust User adjustment of auto offset. Allows user control of brightness.
0x0D Read/Write [7:0] 10000000 Blue Offset Blue offset/target code. 0 = small offset, 255 = large offset.
0x0E Read/Write [7:0] 00100000
1 = full bandwidth.
[0] *******0 Hold Auto Offset 0 = normal auto offset operation.
1 = hold current offset value.
0x1C Read/Write [7] 0******* Auto Offset Enable 0 = manual offset.
1 = auto offset using offset as target code.
[6:5] *10***** Auto Offset 00 = every clamp.
Update Mode 01 = every 16 clamps.
10 = every 64 clamps.
11 = Every Vsync.
[4:3] ***01*** Difference Shift 00 = 100% of difference used to calculate new offset.
Amount 01 = 50%.
10 = 25%.
11 = 12.5%.
[2] *****1** Auto Jump Enable 0 = normal operation.
[1] ******1* Post Filter Enable 0 = disable post filer.
1 = enable post filter.
[0] *******0 Toggle Filter Enable
0x1D Read/Write [7:0] 00001000 Slew Limit Limits the amount the offset can change by in a single update.
0x1E Read/Write [7:0] 32
1 = active high out.
[6] *1****** Vsync Output Polarity Output Vsync polarity (both DVI and analog).
0 = active low out.
1 = active high out.
[5] **1***** DE Output Polarity Output DE polarity (both DVI and analog) .
0 = active low out.
1 = active high out.
[4] ***1**** Field Output Polarity Output field polarity (both DVI and analog).
0 = active low out.
1 = active high out.
[3] ****1*** SOG Output Polarity Output SOG polarity (analog only).
0 = active low out.
1 = active high out.
[2:1] *****11* SOG Output Select Selects signal present on SOG output.
00 = SOG (SOG0 or SOG1).
01 = Raw Hsync (HSYNC0 or HSYNC1).
10 = Regenerated sync.
11 = Hsync to PLL.
[0] *******0 Output CLK Invert 0 = Don’t invert clock out.
1 = Invert clock out.
0x25 Read/Write [7:6] 01****** Output CLK Select
[3:2] ****00** Output Mode Selects which pins the data comes out on.
00 = 4:4:4 mode (normal).
01 = 4:2:2 + DDR 4:2:2 on blue.
10 = DDR 4:4:4 + DDR 4:2:2 on blue.
Read/Write
or Read Only Bits
Default
Value Register Name Description
Enables the PLL to use the filtered Hsync rather than the raw
. This clips any bad Hsyncs, but does not regenerate
Hsync
missing pulses.
Enables the Vsync filter. The Vsync filter gives a predictable
Vsync timing relationship but clips one Hsync period off
Hsync/
the leading edge of Vsync.
Vsync Duration
Enable
Auto Offset Clamp
de
Mo
Auto Offset Clamp
ngth
Le
Hsync Output
larity
Po
Output Drive
ength
Str
Enables the Vsync duration block. This block can be used if
essary to restore the duration of a filtered Vsync.
nec
0 = auto offset measures code during clamp.
1 = auto offset measures code (10 or 16) clock cycles after end of
clamp for 6 clock cycles.
Sets delay after end of clamp for auto offset clamp mode = 1.
Hsync Duration. Sets the duration of the output
clocks.
Output Hsync Polarity (both DVI and Analog). 0 = ac
Select which clock to use on output pin. 1×
from TMDS clock input when pixel repetition is in use.
Set the drive strength of the outputs.
00 = lowest, 11 = highest.
Hsync in pixel
tive low out.
CLK is divided down
Rev. 0 | Page 26 of 64
AD9880
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Hex
Address
11 = 12-bit 4:2:2 (HDMI can have 12-bit 4:2:2 data).
[1] ******1*
[0] *******0
0x26 Read/Write [7] 0******* Output Three-State Three-state the outputs.
[6] *0****** SOG Three-State Three-state the SOG output.
[5] **0***** SPDIF Three-State Three-state the SPDIF output.
[4] ***0**** I2S Three-State Three-state the I2S output and the MCLK out.
[3] ****1***
0 = active low.
1 = active high.
Selects the function of the power-down pin.
[2:1] *****00*
0x2A Read/Write [3:0] ****0101 Line Width MSB MSB, Register 0x2B.
0x2B Read/Write [7:0] 00000000 Line Width Sets the width of the active video line (in pixels).
0x2C Read/Write [3:0] ****0010 Screen Height MSB MSB, Register 0x2D.
0x2D Read/Write [7:0] 11010000 Screen Height Sets the height of the active screen (in lines).
0x2E Read/Write [7] 0******* Ctrl EN Allows Ctrl [3:0] to be output on the I2s data pins.
00 = I2S mode.
[6:5] *00***** I2S Out Mode 01 = right-justified.
10 = left-justified.
11 = raw IEC60958 mode.
[4:0] ***11000 I2S Bit Width Sets the desired bit width for right-justified mode.
Read/Write
or Read Only Bits
Default
Value Register Name Description
Primary Output
Enable
Secondary Output
Enable
Power-Down Pin
larity
Po
Power-Down Pin
nction
Fu
Auto Power-Down
Enable
MCLK External
Enable
Enables primary output.
Enables secondary output (DDR 4:2:2 in O
Sets polarity of power-down pin.
00 = power-down.
0 = disable auto low power state.
Sets the LSB of the address of the HDCP I
second receiver in a dual-link configuration.
If an external MCLK is used then it must be locked to the video
according to the CTS and N available in the I
clock
match between the internal MCLK and the input MCLK results in
dropped or repeated audio samples.
Enables EAV/SAV codes to be inserted into the video output
ta.
da
Sets the difference (in Hsyncs) in field length bet
and Field 1.
Sets the delay (in lines) from Vsync leading edge to the start of
tive video.
ac
Sets the delay (in pixels) from Hsync leading edge t
active video.
utput Modes 1 and 2).
2
C. Set to 1 only for a
2
C. Any mis-
ween Field 0
o the start of
Rev. 0 | Page 27 of 64
AD9880
www.BDTIC.com/ADI
Hex
Address
0x2F Read [6] *0****** TMDS Sync Detect Detects a TMDS DE.
[5] **0***** TMDS Active Detects a TMDS clock.
[4] ***0**** AV Mute Gives the status of AV mute based on general control packets.
[3] ****0*** HDCP Keys Read Returns 1 when read of EEPROM keys is successful.
[2:0] *****000 HDMI Quality Returns quality number based on DE edges.
0x30 Read [6] *0******
[5] **0***** DVI Hsync Polarity Returns DVI Hsync polarity.
[4] ***0**** DVI Vsync Polarity Returns DVI Vsync polarity.
[3:0] ****0000
0x31 Read/Write [7:4] 1001**** MV Pulse Max
[3:0] ****0110 MV Pulse Min Sets the min pseudo sync pulse width for Macrovision detection.
0x32 Read/Write [7] 0******* MV Oversample En
[6] *0****** MV Pal En Tells the Macrovision detection engine to enter PAL mode.
[5:0] **001101 MV Line Count Start Sets the start line for Macrovision detection.
0x33 Read/Write [7] 1******* MV Detect Mode 0 = standard definition.
1 = progressive scan mode.
[6] *0****** MV Settings Override 0 = use hard coded settings for line counts and pulse widths.
1 = use I2C values for these settings.
[5:0] **010101 MV Line Count End Sets the end line for Macrovision detection.
0x34 Read/Write [7:6] 10****** MV Pulse Limit Set
[5] **0***** Low Freq Mode
[4] ***0**** Low Freq Override
[3] ****0*** Up Conversion Mode 0 = Repeat Cr and Cb values.
1 = Interpolate Cr and Cb values.
[2] *****0** CrCb Filter Enable Enables the FIR filter for 4:2:2 CrCb output.
[1] ******0* CSC_Enable
0x35 Read/Write [6:5] *01* **** CSC_Mode 00 = ±1.0, −4096 to 4095
01 =±2.0, −8192 to 8190
1× = ±4.0, −16384 to 16380
[4:0] ***01100 CSC_Coeff_A1 MSB MSB, Register 0x36.
0x36 Read/Write [7:0] 01010010 CSC_Coeff_A1 Color space converter (CSC) coefficient for equation:
G
BB
0x37 Read/Write [4:0] ***01000 CSC_Coeff_A2 MSB MSB, Register 0x38.
0x38 Read/Write [7:0] 00000000 CSC_Coeff_A2 Color space converter (CSC) coefficient for equation:
G
BB
Read/Write
or Read Only Bits
Default
Value Register Name Description
HDMI Content
ypted
Encr
HDMI Pixel
epetition
R
This bit is high when HDCP decryption is in use (content is
protected). The signal goes low when HDCP is not being used.
Customers can use this bit to determine whether or not to allow
copying of the content. The bit should be sampled at regular
intervals since it can change on a frame by frame basis.
Returns current HDMI pixel repetition amount. 0 = 1×, 1 = 2×, ...
The clock and data outputs automatically de-repeat by this
value.
Sets the max pseudo sync pulse width for Macrovision
ection.
det
Tells the Macrovision detection engine whether we are
versampling or not.
o
Sets the number of pulses required in the last 3 lines (SD mode
only).
Sets whether the Audio PLL is in low freq. mode or not. Low
equency mode should only be set for pixel clocks <80 MHz.
fr
Allows the previous bit to be used to set low frequency mode
ather than the internal auto-detect.
r
Enables the color space converter (CSC). The default settings for
the CSC pr
Sets the fixed point position of the CSC coefficients. Including
the A4, B4, C4, offsets
R
OUT
OUT
OUT
R
OUT
OUT
OUT
ovide HDTV to RGB conversion.
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
= (A1 × RIN + (A2 × GIN) + (A3 × BIN) + A4
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
.
Rev. 0 | Page 28 of 64
AD9880
www.BDTIC.com/ADI
Hex
Address
0x39 Read/Write [4:0] ***00000 CSC_Coeff_A3 MSB MSB, Register 0x3A.
0x3A Read/Write [7:0] 00000000 CSC_Coeff_A3 Color space converter (CSC) coefficient for equation:
G
BB
0x3B Read/Write [4:0] ***11001 CSC_Coeff_A4 MSB MSB, Register 0x3C.
0x3C Read/Write [7:0] 11010111 CSC_Coeff_A4 Color space Converter (CSC) coefficient for equation:
G
BB
0x3D Read/Write [4:0] ***11100 CSC_Coeff_B1 MSB MSB, Register 0x3E.
0x3E Read/Write [7:0] 01010100 CSC_Coeff_B1 Color space converter (CSC) coefficient for equation:
R
BB
0x3F Read/Write [4:0] ***01000 CSC_Coeff_B2 MSB MSB, Register 0x40.
0x40 Read/Write [7:0] 00000000 CSC_Coeff_B2 Color space Converter (CSC) coefficient for equation:
R
BB
0x41 Read/Write [4:0] ***11110 CSC_Coeff_B3 MSB MSB, Register 0x42.
0x42 Read/Write [7:0] 10001001 CSC_Coeff_B3 Color space converter (CSC) coefficient for equation:
R
BB
0x43 Read/Write [4:0] ***00010 CSC_Coeff_B4 MSB MSB, Register 0x44.
0x44 Read/Write [7:0] 10010010 CSC_Coeff_B4 Color space converter (CSC) coefficient for equation:
R
BB
0x45 Read/Write [4:0] ***00000 CSC_Coeff_C1 MSB MSB, Register 0x46.
0x46 Read/Write [7:0] 00000000 CSC_Coeff_C1 Color space converter (CSC) coefficient for equation:
R
G
0x47 Read/Write [4:0] ***01000 CSC_Coeff_C2 MSB MSB, Register 0x48.
0x48 Read/Write [7:0] 00000000 CSC_Coeff_C2 Color space converter (CSC) coefficient for equation:
R
G
BB
0x49 Read/Write [4:0] ***01110 CSC_Coeff_C3 MSB MSB, Register 0x4A.
0x4A Read/Write [7:0] 10000111 CSC_Coeff_C3 Color space converter (CSC) coefficient for equation:
R
G
0x4B Read/Write [4:0] ***11000 CSC_Coeff_C4 MSB MSB, Register 0x4C.
0x4C Read/Write [7:0] 10111101 CSC_Coeff_C4 Color space Converter (CSC) coefficient for equation:
R
G
Read/Write
or Read Only Bits
Default
Value Register Name Description
R
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
R
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
G
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
G
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN + (A2 × GIN) + (A3 × BIN) + A4
OUT
G
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × RIN) + (A3 × BIN) + A4
OUT
G
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
BB
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
BB
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
B
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
B
OUT
Rev. 0 | Page 29 of 64
AD9880
www.BDTIC.com/ADI
Hex
Address
0x50 Read/Write [7:0] 00100000 Test Must be written to 0x20 for proper operation.
0x56 Read/Write [7:0] 00001111 Test Must be written to default 0x0F for proper operation.
0x57 Read/Write [7] 0******* A/V Mute Override A1 overrides the AV mute value with Bit 6.
[6] *0****** AV Mute Value Sets AV mute value if override is enabled.
[3] ****0*** Disable Video Mute Disables mute of video during AV mute.
[2] *****0** Disable Audio Mute Disables mute of audio during AV mute.
0x58 Read/Write [7] MCLK PLL Enable MCLK PLL enable—uses analog PLL.
[6:4] MCLK PLL_N
[3] N_CTS_Disable
[2:0] MCLK FS_N
0x59 Read/Write [6] MDA/MCL PU This disables the MDA/MCL pull-ups.
[5] CLK Term O/R Clock termination power-down override 0 = auto, 1 = manual.
[4] Manual CLK Term Clock termination: 0 = normal, 1 = disconnected.
[2] FIFO Reset UF This bit resets the audio FIFO if underflow is detected.
[1] FIFO Reset OF This bit resets the audio FIFO if overflow is detected.
[0]
0x5A Read [6:0] Packet Detected
0 AVI infoframe.
1 Audio infoframe.
2 SPD infoframe.
3 MPEG source infoframe.
4 ACP packets.
5 ISRC1 packets.
6 ISRC2 packets.
0x5B Read [3] HDMI Mode 0 = DVI, 1 = HDMI.
0x5E Read [7:6] Channel Status Mode = 00. All others are reserved.
[5:3]
2
1
0 0 = consumer use of channel status block.
0x5F Read [7:0]
0x60 Read [7:4] Channel Number
[3:0] Source Number
0x61 Read [5:4] Clock Accuracy Clock accuracy.
00 = Level II.
01 = Level III.
10 = Level I.
11 = reserved.
[3:0] Sampling 0011 = 32 kHz.
Read/Write
or Read Only Bits
Default
Value Register Name Description
MCLK PLL N [2:0]—this controls the division of the MCLK out of
= /2, 2 = /3, 3 = /4, etc.
s, 2 = 384, 7 = 1024 fs.
e word used for other purposes.
MDA/MCL Three-
te
Sta
Audio Channel Status
Channel Status
gory Code
Cate
the PLL: 0 = /1, 1
Prevents the N/CTS packet on the link from writing to the N and
S registers.
CT
Controls the multiple of 128 fs used for MCLK out . 0 = 128 fs,
1 = 256 f
This bit three-states the MDA/MCL lines.
These 7 bits are updated if any specific packet has been received
e last reset or loss of clock detect. Normal is 0x00.
sinc
BitData Packet Detected
When Bit 1 = 0 (Linear PCM).
000 = 2 audio channe
001 = 2 audio channels with 50/15 μs pre-emphasis.
010 = reserved.
011 = reserved.
0 = Software for which copyright is asserted.
oftware for which no copyright is asserted.
1 = S
0 = audio sample word represents linear PCM samples.
0x80 Read [7:0] AVI Infoframe Version
0x81 Read [6:5] Y [1:0] Indicates RGB, 4:2:2 or 4:4:4.
00 = RGB.
01 = YCbCr 4:2:2.
10 = YCbCr 4:4:4.
4 Active Format Active format information present.
Information Status 0 = no data.
1 = active format information valid.
[3:2] Bar Information B [1:0].
00 = no bar information.
01 = horizontal bar information valid.
10 = vertical bar information valid.
11 = horizontal and vertical bar information valid.
[1:0] Scan Information S [1:0].
00 = no information.
01 = overscanned (television).
10 = underscanned (computer).
0x82 Read [7:6] Colorimetry C [1:0].
00 = no data.
01 = SMPTE 170M, ITU601.
10 = ITU709.
[5:4] Picture Aspect Ratio M [1:0].
00 = no data.
Read/Write
or Read Only Bits
Default
Value Register Name Description
Cycle time stamp—this 20-bit value is used with the N value to
egenerate an audio clock. For remaining bits see Register 0x7C
r
and Register 0x7D.
20-bit N used with CTS to regenerate the audio clock. For
emaining bits, see Register 0x7E and Register 0x7F.
00 = no known non-uniform scaling.
01 = picture has been scaled horizontally.
10 = picture has been scaled vertically.
11 = picture has been scaled horizontally and vertically.
0x84 Read [6:0]
0x85 Read [3:0] Pixel Repeat
0000 = no repetition—pixel sent once.
0001 = pixel sent twice (repeated once).
0010 = pixel sent 3 times.
1001 = pixel sent 10 times.
0xA—0xF reserved.
0x86 Read [7:0] Active Line Start LSB
0x87 Read [6:0] New Data Flags
0 AVI Infoframe.
1 audio Infoframe.
2 SPD Infoframe.
3 MPEG source Infoframe.
4 ACP packets.
5 ISRC1 packets.
6 ISRC2 packets.
0x88 Read [7:0] Active Line Start MSB Active line start MSB (see Register 0x86).
0x89 Read [7:0] Active Line End LSB
0x8A Read [7:0] Active Line End MSB Active line end MSB. See Register 0x89.
0x8B Read [7:0] Active Pixel Start LSB
0x8C Read [7:0] Active Pixel Start MSB Active pixel start MSB. See Register 0x8B.
0x8D Read [7:0] Active Pixel End LSB
0x8E Read [7:0] Active Pixel End MSB Active pixel end MSB. See Register 0x8D.
0x8F Read [6:0] New Data Flags New Data Flags (see 0x87).
Read/Write
or Read Only Bits
Default
Value Register Name Description
Active Format Aspect
tio
Ra
Nonuniform Picture
aling
Sc
Video Identification
de
Co
R [3:0].
SC[1:0].
VIC [6:0] video identification code—refer to CEA EDID short
video descriptors.
PR [3:0]—This specifies how many times a pixel has been
peated.
re
This represents the line number of the end of the top horizontal
. If 0, there is no horizontal bar. Combines with Register 0x88
bar
for a 16 bit value.
New data flags. These 8 bits are
changes. Normal (no NDFs) is 0x00. When any NDF register is
read, all bits reset to 0x00. All NDF registers contain the same
data.
BitData Packet Changed
This represents the line number of the beginning of a lower
izontal bar. If greater than the number of active video lines,
hor
there is no lower horizontal bar. Combines with Register 0x8A
for a 16-bit value.
This represents the last pixel in a vertical pillar-bar at the left side
of the pic
0x8C for a 16-bit value.
This represents the first hor
the right side of the picture. If greater than the maximum
number of horizontal pixels, there is no vertical bar. Combines
with Register 0x8E for a16-bit value.
ture. If 0, there is no left bar. Combines with Register
7 Down-Mix DM_INH—down-mix inhibit.
0 = permitted or no information.
1 = prohibited.
0x95 Read [6:3] Level Shift LSV [3:0]—level shift values with attenuation information.
0000 = 0 dB attenuation.
0001 = 1 dB attenuation.
1111 = 15 dB attenuation.
0x96 Read [7:0] Reserved.
0x97 Read [6:0] New Data Flags New data flags (see 0x87).
0x98 Read [7:0]
0x99 Read [7:0]
Read/Write
or Read Only Bits
Default
Value Register Name Description
Audio Infoframe
rsion
Ve
Source Product Description (SPD) Infoframe
Source Product
cription (SPD)
Des
Infoframe Version
Vender Name
ter 1
Charac
Max bit rate (compressed audio only).The value of this field
multiplied b
CA [7:0]. Speaker mapping or placement for up to 8 channels.
ee table 91 in detailed description.
S
…..
Vender name character 1 (VN1) (7-bit ASCII code)—This is the
first character in 8 that is the name of the company that appears
on the product.
y 8 kHz represents the maximum bit rate.
Rev. 0 | Page 33 of 64
AD9880
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Hex
Address
0x9A Read [7:0] VN2 VN2.
0x9B Read [7:0] VN3 VN3.
0x9C Read [7:0] VN4 VN4.
0x9D Read [7:0] VN5 VN5.
0x9E Read [7:0] VN6 VN6.
0x9F Read [6:0] New Data Flags New data flags (see 0x87).
0xA0 Read [7:0] VN7 VN7.
0xA1 Read [7:0] VN8 VN8.
0xA2 Read [7:0]
0xA3 Read [7:0] PD2 PD2.
0xA4 Read [7:0] PD3 PD3.
0xA5 Read [7:0] PD4 PD4.
0xA6 Read [7:0] PD5 PD5.
0xA7 Read [7:0] New Data Flags New data flags (see 0x87).
0xA8 Read [6:0] PD6 PD6.
0xA9 Read [7:0] PD7 PD7.
0xAA Read [7:0] PD8 PD8.
0xAB Read [7:0] PD9 PD9.
0xAC Read [7:0] PD10 PD10.
0xAD Read [7:0] PD11 PD11.
0xAE Read [7:0] PD12 PD12.
0xAF Read [6:0] New Data Flags New data flags (see 0x87).
0xB0 Read [7:0] PD13 PD13.
0xB1 Read [7:0] PD14 PD14.
0xB2 Read [7:0] PD15 PD15.
0xB3 Read [7:0] PD16 PD16.
0xB4 Read [7:0] Source Device This is a code that classifies the source device.
Information Code 0x00 = unknown.
0x01 = Digital STB.
0x02 = DVD.
0x03 = D-VHS.
0x04 = HDD video.
0x05 = DVC.
0x06 = DSC.
0x07 = Video CD.
0x08 = Game.
0x09 = PC general.
0xB7 Read [6:0] New Data Flags New data flags (see 0x87).
0xB8 Read [7:0]
0xB9 Read [7:0] MB(0)
0xBA Read [7:0] MB[1] MB [1].
0xBB Read [7:0] MB[2] MB [2].
0xBC Read [7:0] MB [3] (upper byte).
4 Field Repeat FR—New field or repeated field.
0 = New field or picture.
1 = Repeated field.
Read/Write
or Read Only Bits
Default
Value Register Name Description
Product Description
ter 1
Charac
MPEG Source Infoframe
MPEG Source
foframe Version
In
Product Description Character 1 (PD1) (7-bit ASCII code)—This is
the first character of 16 that contains the model number and a
short description.
MB [0] (Lower byte of MPEG bit rate: Hz) This is the lower 8 bits of
32 bits (4 b
ytes) that specify the MPEG bit rate in Hz.
Rev. 0 | Page 34 of 64
AD9880
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Hex
Address
0xBD Read [1:0] MPEG Frame MF [1:0] This identifies whether frame is an I, B, or P picture.
00 = unknown.
01 = I picture.
10 = B picture.
11 = P picture.
0xBE Read [7:0] Reserved.
0xBF Read [6:0] New Data Flags New data flags (see 0x87).
0xC0 Read [7:0] Audio content protection packet (ACP) type.
0x00 = Generic audio.
0x01 = IEC 60958-identified audio.
0x02 = DVD-audio.
0x03 = Reserved for super audio CD (SACD).
0xC1 Read [7:0] ACP Packet Byte 0 ACP Packet Byte 0 (ACP_PB0).
0xC2 Read [7:0] ACP_PB1 ACP_PB1.
0xC3 Read [7:0] ACP_PB2 ACP_PB2.
0xC4 Read [7:0] ACP_PB3 ACP_PB3.
0xC5 Rea [7:0] ACP_PB4 ACP_PB4.
0xC6 Read [7:0] ACP_PB5 ACP_PB5.
0xC7 Read [6:0] NDF New data flags (see 0x87).
0xC8 7 ISRC1 Continued
An 8-bit value that reflects the current chip revision.
PLL DIVIDER CONTROL
0x01 7-0 PLL Divide Ratio MSBs
The eight most significant bits of the 12-bit PLL divide
ratio PLLDIV.
The PLL derives a pixel clock from the incoming
sync signal. The pixel clock frequency is then
H
divided by an integer value, such that the output is
phase-locked to Hsync. This PLLDIV value
determines the number of pixel times (pixels plus
horizontal blanking overhead) per line. This is
typically 20% to 30% more than the number of active
pixels in the display.
The 12-bit value of the PLL divider supports divide
ra
tios from 221 to 4095. The higher the value loaded
in this register, the higher the resulting clock
frequency with respect to a fixed Hsync frequency.
VESA has established some standard timing
sp
ecifications, which assists in determining the value
for PLLDIV as a function of horizontal and vertical
display resolution and frame rate (see Tabl e 8).
However, many computer systems do not conform
recisely to the recommendations, and these numbers
p
should be used only as a guide. The display system
manufacturer should provide automatic or manual
means for optimizing PLLDIV. An incorrectly set
PLLDIV usually produces one or more vertical noise
bars on the display. The greater the error, the greater
the number of bars produced.
The power-up default value of PLLDIV is 1693
(P
LLDIVM = 0x69, PLLDIVL = 0xDx)
The AD9880 updates the full divide ratio only when
t
he LSBs are changed. Writing to this register by itself
does not trigger an update.
0x02 7-4 PLL Divide Ratio LSBs
The four least significant bits of the 12-bit PLL divide
ratio PLLDIV.
CLOCK GENERATOR CONTROL
0x03 7-6 VCO Range Select
Two bits that establish the operating range of the clock
generator. VCORNGE must be set to correspond with
the desired operating frequency (incoming pixel rate).
The PLL gives the best jitter performance at high frequencies. For this reason, to output low pixel rates and
still get good jitter performance, the PLL actually
operates at a higher frequency but then divides down
the clock rate. Tabl e 12 shows the pixel rates for each
VCO range setting. The PLL output divisor is automatically selected with the VCO range setting.
Table 12. VCO Ranges
VCO Range Pixel Rate Range
00 12 to 30
01 30 to 60
10 60 to 120
11 120 to 150
The power-up default value is 01.
5-3 Charge Pump Current
Three bits that establish the current driving the loop
filter in the clock generator.
This bit determines the source of the pixel clock.
Table 14. External Clock Select Settings
EXTCLK Function
0 Internally generated clock.
1 Externally provided clock signal
A Logic 0 enables the internal PLL that generates the
pixel clock from an externally provided Hsync.
The power-up default value of PLLDIV is 1693
LLDIVM = 0x69, PLLDIVL = 0xDx).
(P
Rev. 0 | Page 37 of 64
A Logic 1 enables the external CKEXT input pin. In
his mode, the PLL divide ratio (PLLDIV) is ignored.
t
The clock phase adjusts (phase is still functional). The
power-up default value is EXTCLK = 0.
AD9880
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0x04 7-3 Phase Adjust
These bits provide a phase adjustment for the DLL to
generate the ADC clock. A 5-bit value that adjusts the
sampling phase in 32 steps across one pixel time. Each
step represents an 11.25° shift in sampling phase. The
power up default is 16.
0x09 7-0 Red Channel Offset
These eights bits are the red channel offset control.
The offset control shifts the analog input, resulting in
a change in brightness. Note that the function of the
offset register depends on whether clamp feedback is
enabled (Register 0x1C, Bit 7 = 1).
INPUT GAIN
0x05 7-0 Red Channel Gain
These bits control the programmable gain amplifier
(PGA) of the red channel. The AD9880 can accommodate input signals with a full-scale range of
between 0.5 V and 1.0 V p-p. Setting the red gain to
255 corresponds to an input range of 1.0 V. A red gain
of 0 establishes an input range of 0.5 V. Note that
increasing red gain results in the picture having less
contrast (the input signal uses fewer of the available
converter codes). The power-up default is 0x80.
0x06 7-0 Green Channel Gain
These bits control the PGA of the green channel. The
AD9880 can accommodate input signals with a fullscale range of between 0.5 V and 1.0 V p-p. Setting the
green gain to 255 corresponds to an input range of 1.0
V. A green gain of 0 establishes an input range of 0.5 V.
Note that increasing green gain results in the picture
having less contrast (the input signal uses fewer of the
available converter codes). The power-up default is
0x80.
0x07 7-0 Blue Channel Gain
These bits control the PGA of the blue channel. The
AD9880 can accommodate input signals with a fullscale range of between 0.5 V and 1.0 V p-p. Setting the
blue gain to 255 corresponds to an input range of
1.0 V. A blue gain of 0 establishes an input range of
0.5 V. Note that increasing blue gain results in the
picture having less contrast (the input signal uses
fewer of the available converter codes). The power-up
default is 0x80.
INPUT OFFSET
0x08 7-0 Red Channel Offset Adjust
If clamp feedback is enabled, the 8-bit offset adjust
determines the clamp code. The 8-bit offset adjust is a
twos complement number consisting of 1 sign bit plus
7 bits (0x7F = +127, 0x00 = 0, 0xFF = −1, and 0x80 =
−128). For example, if the register is programmed to
130d, then the output code is equal to 130d at the end
of the clamp period. Note that incrementing the offset
register setting by 1 LSB adds 1 LSB of offset,
regardless of the clamp feedback setting.
The power-up default is 0.
If clamp feedback is disabled, the offset register bits
ntrol the absolute offset added to the channel. The
co
offset control provides a +127/−128 LSBs of adjustment range, with one LSB of offset corresponding to
1 LSB of output code. If clamp feedback is enabled
these bits provide the relative offset (brightness) from
the offset adjust in the previous register. The power-up
default is 0x80.
0x0A 7-0 Green Channel Offset Adjust
If clamp feedback is enabled, the 8-bit offset adjust
determines the clamp code. The 8-bit offset adjust is a
twos complement number consisting of 1 sign bit plus
7 bits (0x7F = +127, 0x00 = 0, 0xFF = −1, and 0x80 =
−128). For example, if the register is programmed to
130d, then the output code is equal to 130d at the end
of the clamp period. Note that incrementing the offset
register setting by 1 LSB adds 1 LSB of offset, regardless of the clamp feedback setting. The power-up
default is 0.
0x0B 7-0 Green Channel Offset
These eight bits are the green channel offset control.
The offset control shifts the analog input, resulting in
a change in brightness. Note that the function of the
offset register depends on whether clamp feedback is
enabled (Register 0x1C, Bit 7 = 1).
If clamp feedback is disabled, the offset register bits
ntrol the absolute offset added to the channel. The
co
offset control provides a +127/−128 LSBs of adjustment range, with one LSB of offset corresponding to
1 LSB of output code. If clamp feedback is enabled
these bits provide the relative offset (brightness) from
the offset adjust in the previous register. The power-up
default is 0x80.
0x0C 7-0 Blue Channel Offset Adjust
If clamp feedback is enabled, the 8-bit offset adjust
determines the clamp code. The 8-bit offset adjust is a
twos complement number consisting of 1 sign bit plus
7 bits (0x7F = +127, 0x00 = 0, 0xFF = −1, and 0x80 =
−128). For example, if the register is programmed to
130d, then the output code is equal to 130d at the end
of the clamp period. Note that incrementing the offset
register setting by 1 LSB adds 1 LSB of offset, regardless of the clamp feedback setting. The power-up
default is 0.
Rev. 0 | Page 38 of 64
AD9880
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0x0D 7-0 Blue Channel Offset
These eight bits are the blue channel offset control.
The offset control shifts the analog input, resulting in
a change in brightness. Note that the function of the
offset register depends on whether clamp feedback is
enabled (Register 0x1C, Bit 7 = 1).
If clamp feedback is disabled, the offset register bits
ntrol the absolute offset added to the channel. The
co
offset control provides a +127/−128 LSBs of adjustment range, with 1 LSB of offset corresponding to
1 LSB of output code. If clamp feedback is enabled
these bits provide the relative offset (brightness) from
the offset adjust in the previous register. The power-up
default is 0x80.
SYNC
0x0E 7-0 Sync Separator
Selects the max Hsync pulse width for composite sync
separation. Power-down default is 0x20.
0x0F 7-2 SOG Comparator Threshold Enter
The enter level for the SOG slicer. Must be < than exit
level (Register 0x10). The power-up default is 0x10.
0x10 7-2 SOG Comparator Threshold Exit
The exit level for the SOG slicer. Must be > enter level
(Register 0x0F). The power-up default is 0x10.
0x11 7 Hsync Source
0 = Hsync, 1 = SOG. The power-up default is 0. These
selections are ignored if Register 0x11, Bit 6 = 0.
0x11 6 Hsync Source Override
0 = auto Hsync source, 1 = manual Hsync source.
Manual Hsync source is defined in Register 0x11,
Bit 7. The power-up default is 0.
0x11 5 Vsync Source
0 = Vsync, 1 = Vsync from SOG. The power-up
default is 0. These selections are ignored if Register
0x11, Bit 4 = 0.
0x11 4 Vsync Source Override
0 = auto Vsync source, 1 = MANUAL Vsync source.
Manual Vsync source is defined in Register 0x11,
Bit 5. The power-up default is 0.
0x11 2 Channel Select Override
0 = auto channel select, 1 = manual channel select.
Manual channel select is defined in Register 0x11,
Bit 3. The power-up default is 0.
0x11 1 Interface Select
0 = analog interface, 1 = digital interface. The powerup default is 0. These selections are ignored if
Register 0x11, Bit 0 = 0.
0x11 0 Interface Select Override
0 = auto interface select, 1 = manual interface select.
Manual interface select is defined in Register 0x11,
Bit 1. The power-up default is 0.
0x12 7 Input Hsync Polarity
0 = active low, 1 = active high. The power-up default is
1. These selections are ignored if Register 10x2,
Bit 6 = 0.
0x12 6 Hsync Polarity Override
0 = auto Hsync polarity, 1 = manual Hsync polarity.
Manual Hsync polarity is defined in Register 0x11,
Bit 7. The power-up default is 0.
0x12 5 Input Vsync Polarity
0 = active low, 1 = active high. The power-up default is
1. These selections are ignored if Register 0x11,
Bit 4 = 0.
0x12 4 Vsync Polarity Override
0 = auto Vsync polarity, 1 = manual Vsync polarity.
Manual Vsync polarity is defined in Register 0x11,
Bit 5. The power-up default is 0.
COAST AND CLAMP CONTROLS
0x12 3 Input Coast Polarity
0 = active low, 1 = active high. The power-up default
is 1.
0x12 2 Coast Polarity Override
0 = auto Coast polarity, 1 = manual Coast polarity.
The power-up default is 0.
0x12 1 Coast Source
0 = internal Coast, 1 = external Coast. The power-up
default is 0.
0x11 3 Channel Select
0 = Channel 0, 1 = Channel 1. The power-up default is
0. These selections are ignored if Register 0x11,
Bit 2 = 0.
Rev. 0 | Page 39 of 64
0x12 0 Filter Coast Vsync
0 = use raw Vsync for Coast generation, 1 = use
filtered Vsync for Coast generation The power-up
default is 1.
AD9880
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0x13 7-0 Precoast
This register allows the internally generated Coast
signal to be applied prior to the Vsync signal. This is
necessary in cases where pre-equalization pulses are
present. The step size for this control is one Hsync
period. For Precoast to work correctly, it is necessary
for the Vsync filter (0x21, Bit 5) and sync processing
filter (0x21 Bit 7) both to be either enabled or
disabled. The power-up default is 0.
0x14 7-0 Postcoast
This register allows the internally generated Coast
signal to be applied following the Vsync signal. This is
necessary in cases where post-equalization pulses are
present. The step size for this control is one Hsync
period. For Postcoast to work correctly, it is necessary
for the Vsync filter (0x21, Bit 5) and sync processing
filter (0x21, Bit 7) both to be either enabled or
disabled. The power-up default is 0.
STATUS OF DETECTED SIGNALS
0x15 7 Hsync0 Detection Bit
Indicates if Hsync0 is active. This bit is used to
indicate when activity is detected on the Hsync0 input
pin. If Hsync is held high or low, activity is not
detected. The sync processing block diagram shows
where this function is implemented. 0 = Hsync0 not
active. 1 = Hsync0 is active.
Table 15. Hsync0 Detection Results
Detect Result
0 No activity detected
1 Activity detected
0x15 6 Hsync1 Detection Bit
Indicates if Hsync1 is active. This bit is used to indicate when activity is detected on the Hsync1 input pin.
If Hsync is held high or low, activity is not detected.
The sync processing block diagram shows where this
function is implemented. 0 = Hsync1 not active.
1 = Hsync1 is active.
Table 16. Hsync1 Detection Result
Detect Result
0 No activity detected
1 Activity detected
0x15 5 Vsync0 Detection Bit
Indicates if Vsync0 is active. This bit is used to
indicate when activity is detected on the Vsync0 input
pin. If Vsync is held high or low, activity is not
detected. The sync processing block diagram shows
where this function is implemented. 0 = Vsync0 not
active. 1 = Vsync0 is active.
Table 17. Vsync0 Detection Results
Detect Result
0 No activity detected
1 Activity detected
0x15 4 Vsync1 Detection Bit
Indicates if Vsync1 is active. This bit is used to
indicate when activity is detected on the Vsync1 input
pin. If Vsync is held high or low, activity is not
detected. The sync processing block diagram shows
where this function is implemented. 0 = Vsync1 not
active. 1 = Vsync1 is active.
Table 18. Vsync1 Detection Results
Detect Result
0 No activity detected
1 Activity detected
0x15 3 SOG0 Detection Bit
Indicates if SOG0 is active. This bit is used to indicate
when activity is detected on the SOG0 input pin. If
SOG is held high or low, activity is not detected. The
sync processing block diagram shows where this
function is implemented. 0 = SOG0 not active.
1 = SOG0 is active.
Table 19. SOG0 Detection Result
Detect Result
0 No activity detected
1 Activity detected
0x15 2 SOG1 Detection Bit
Indicates if SOG1 is active. This bit is used to indicate
when activity is detected on the SOG1 input pin. If
SOG is held high or low, activity is not detected. The
sync processing block diagram shows where this
function is implemented. 0 = SOG1 not active.
1 = SOG1 is active.
Table 20. SOG1 Detection Results
Detect Result
0 No activity detected
1 Activity detected
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0x15 1 Coast Detection Bit
This bit detects activity on the EXTCLK/EXTCOAST
pin. It indicates that one of the two signals is active,
but it doesn’t indicate if it is EXTCLK or EXTCOAST.
A dc signal is not detected.
Indicates whether sync filter is locked to periodic sync
signals. 0 = sync filter locked to periodic sync signal.
1 = sync filter not locked.
Table 27. Sync Filter Lock Detect
Detect Result
0 Sync filter locked to periodic sync signal
1 Sync filter not locked to periodic sync signal
0x16 0 Bad Sync Detect
0x17 3-0 Hsyncs per Vsync MSBs
The 4 MSBs of the 12-bit counter that reports the
number of Hsyncs/Vsync on the active input. This is
useful in determining the mode and an aid in setting
the PLL divide ratio.
0x18 7-0 Hsyncs per Vsync LSBs
The 8 LSBs of the 12-bit counter that reports the
number of Hsyncs/Vsync on the active input.
0x19 7-0 Clamp Placement
Number of pixel clocks after trailing edge of Hsync to
begin clamp. The power-up default is 8.
0x1A 7-0 Clamp Duration
Number of pixel clocks to clamp. The power-up
default is 0x14.
0x1B 7 Red Clamp Select
This bit selects whether the red channel is clamped to
ground or midscale. Ground clamping is used for red
in RGB applications and midscale clamping is used in
YPrPb (YUV) applications.
Table 28. Red Clamp
Select Result
0 Channel clamped to ground during clamping period
1 Channel clamped to midscale during clamping period
The power-up default is 0.
0x1B 6 Green Clamp Select
This bit selects whether the green channel is clamped
to ground or midscale. Ground clamping is normally
used for green in RGB applications and YPrPb (YUV)
applications.
Table 29. Green Clamp
Select Result
0 Channel clamped to ground during clamping period
1 Channel clamped to midscale during clamping period
The power-up default is 0.
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0x1B 5 Blue Clamp Select
This bit selects whether the blue channel is clamped to
ground or midscale. Ground clamping is used for blue
in RGB applications and midscale clamping is used in
YPrPb (YUV) applications.
Table 30. Blue Clamp
Select Result
0 Channel clamped to ground during clamping period
1 Channel clamped to midscale during clamping period
The power-up default is 0.
0x1B 4 Clamp During Coast
This bit permits clamping to be disabled during
Coast. The reason for this is video signals are
generally not at a known backporch or midscale
position during Coast.
Table 31. Clamp During Coast
Select Result
0 Clamping during Coast is disabled
1 Clamping during Coast is enabled
0 Normal auto offset operation
1 Hold current offset value
The power-up default is 0.
0x1C 7 Auto Offset Enable
0 = manual offset
1 = auto offset using offset as target code. The powerup default is 0.
0x1C 6-5 Auto Offset Update Mode
00 = every clamp
01 = every 16 clamps
10 = every 64 clamps
11 = every Vsync
The power-up default setting is 10.
0x1C 4-3 Difference Shift Amount
00 = 100% of difference used to calculate new offset
01 = 50%
10 = 25%
11 = 12.5%
The power-up default is 01.
0x1C 2 Auto Jump Enable
0 = normal operation
1 = if the code >15 codes off, the offset is jumped to
the predicted offset necessary to fix the >15 code mismatch. The power-up default is 1.
0x1C 1 Post Filter Enable
The post filter reduces the update rate by 1/6 and
requires that all six updates recommend a change
before changing the offset. This prevents unwanted
offset changes.
0 = disable post filer
1 = ena
ble post filter
The power-up default is 1.
0x1C 0 Toggle Filter Enable
The toggle filter looks for the offset to toggle back and
forth and holds it if triggered. This is to prevent
toggling in case of missing codes in the PGA.
1 = toggle filter on, 0 = toggle filter off.
The power-up default is 0.
0x1D 7-0 Slew Limit
Limits the amount the offset can change by in a single
update. The power-up default is 0x08.
0x1E 7-0 Sync Filter Lock Threshold
This 8-bit register is programmed to set the number
of valid Hsyncs needed to lock the sync filter. This
ensures that a consistent, stable Hsync is present
before attempting to filter. The power-up default
setting is 32d.
0x1F 7-0 Sync Filter Unlock Threshold
This 8-bit register is programmed to set the number of
missing or invalid Hsyncs needed to unlock the sync
filter. This disables the filter operation when there is
no longer a stable Hsync signal. The power-up default
setting is 50d.
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0x20 7-0 Sync Filter Window Width
This 8-bit register sets the distance in 40 MHz clock
periods (25 ns), which is the allowed distance for
Hsync pulses before and after the expected Hsync
edge. This is the heart of the filter in that it only looks
for Hsync pulses at a given time (plus or minus this
window) and then ignores extraneous equalization
pulses that disrupt accurate PLL operation. The
power-up default setting is 10d, or 200 ns on either
side of the expected Hsync.
0x21 7 Sync Processing Filter Enable
This bit selects which Hsync is used for the sync
processing functions of internal Coast, H/V count,
field detection, and Vsync duration counts. A clean
Hsync is fundamental to accurate processing of the
sync. The power-up default setting is 1.
Table 35. Sync Processing Filter Enable
Select Result
0 Sync processing uses raw Hsync or SOG
1
Sync processing uses regenerated Hsync from sync
er
filt
0x21 6 PLL Sync Filter Enable
This bit selects which signal the PLL uses. It can select
between raw Hsync or SOG, or filtered versions. The
filtering of the Hsync and SOG can eliminate nearly
all extraneous transitions which have traditionally
caused PLL disruption. The power-up default setting
is 0.
Table 36. PLL Sync Filter Enable
Select Result
0 PLL uses raw Hsync or SOG inputs
1 PLL uses filtered Hsync or SOG inputs
0x21 5 Vsync Filter Enable
The purpose of the Vsync filter is to guarantee the
position of the Vsync edge with respect to the Hsync
edge and to generate a field signal. The filter works by
examining the placement of Vsync and regenerating a
correctly placed Vsync one line later. The Vsync is
first checked to see whether it occurs in the Field 0
position or the Field 1 position. This is done by
checking the leading edge position against the sync
separator threshold and the Hsync position. The
Hsync width is divided into four quadrants with
Quadrant 1 starting at the Hsync leading edge plus a
sync separator threshold. If the Vsync leading edge
occurs in Quadrant 1 or 4 then the field is set to 0 and
the output Vsync is placed coincident with the Hsync
leading edge. If the Vsync leading edge occurs in
Quadrant 2 or 3 then the field is set to 1 and the
output Vsync leading edge is placed in the center of
the line. In this way, the Vsync filter creates a
Table 37. Vsync Filter Enable
Vsync Filter Bit Result
0 Vsync filter disabled
1 Vsync filter enabled
0x21 4 Vsync Duration Enable
Table 38. Vsync Duration Enable
Vsync
Duration Bit
0 Vsync output duration unchanged
1 Vsync output duration set by 0x22
0x21 3 Auto Offset Clamp Mode
Table 39. AO Clamp Mode
AO
Offset Mode Result
0
1 Auto offset measurement is set by 0x21, Bit 2
0x21 2 Auto Offset Clamp Length
Table 40. AO Clamp Length
AO Offset
Clamp Bit Result
0 Delay is 10 clock cycles
1 Delay is 16 clock cycles
0x22 7-0 Vsync Duration
predictable relative position between Hsync and
Vsync edges at the output.
If the Vsync occurs near the Hsync edge, this guaran-
ees that the Vsync edge follows the Hsync edge. This
t
performs filtering also in that it requires a minimum
of 64 lines between Vsyncs. The Vsync filter cleans up
extraneous pulses that might occur on the Vsync. This
should be enabled whenever the Hsync/Vsync count is
used. Setting this bit to 0 disables the Vsync filter.
Setting this bit to 1 enables the Vsync filter. Power-up
default is 0.
This enables the Vsync duration block which is
designed to be used with the Vsync filter. Setting the
bit to 0 leaves the Vsync output duration unchanged;
setting the bit to 1 sets the Vsync output duration
based on Register 0x22. The power-up default is 0.
Result
This bit specifies if the auto offset measurement takes
place during clamp or either 10 or 16 clocks afterward.
The measurement takes 6 clock cycles.
Auto offset measurement takes place during
clamp p
This bit sets the delay following the end of the clamp
period for AO measurement. This bit is valid only if
Register 0x21, Bit 3 = 1.
This is used to set the output duration of the Vsync,
and is designed to be used with the Vsync filter. This
is valid only if Register 0x21, Bit 4 is set to 1. Power-up
default is 4.
eriod
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0x23 7-0 Hsync Duration
An 8 bit register that sets the duration of the Hsync
output pulse. The leading edge of the Hsync output is
triggered by the internally generated, phase-adjusted
PLL feedback clock. The AD9880 then counts a
number of pixel clocks equal to the value in this
register. This triggers the trailing edge of the Hsync
output, which is also phase-adjusted. The power-up
default is 32.
0x24 7 Hsync Output Polarity
This bit sets the polarity of the Hsync output. Setting
this bit to 0 sets the Hsync output to active low. Setting
this bit to 1 sets the Hsync output to active high.
Power-up default setting is 1.
This bit sets the polarity of the Vsync output (both
DVI and analog). Setting this bit to 0 sets the Vsync
output to active low. Setting this bit to 1 sets the Vsync
output to active high. Power-up default is 1.
Table 42. Vsync Output Polarity Settings
Vsync Output Polarity Bit Result
0 Vsync output polarity is negative
1 Vsync output polarity is positive
0x24 5 Display Enable Output Polarity
This bit sets the polarity of the display enable (DE) for
both DVI and analog.
Table 43. DE Output Polarity Settings
DE Output Polarity Bit Result
0 DE output polarity is negative
1 DE output polarity is positive
The power-up default is 1.
0x24 4 Field Output Polarity
This bit sets the polarity of the field output signal on
Pin 21. The power-up default setting is 1.
Table 44. Field Output Polarity
Select Result
0 Active low = even field; active high = odd field
1 Active low = odd field; active high = even field
Output field polarity (both DVI and analog)
0 = active low out
1 = active high out
The power-up default is 1.
0x24 3 SOG Output Polarity
This bit sets the polarity of the SOGOUT signal
(analog only).
Table 45. SOGOUT Polarity Settings
SOGOUT Result
0 Active low
1 Active high
The power-up default setting is 1.
0x24 2-1 SOG Output Select
These register bits control the output on the SOGOUT
pin. Options are the raw SOG from the slicer (this is
the unprocessed SOG signal produced from the sync
slicer), the raw Hsync, the regenerated sync from the
sync filter, which can generate missing syncs because
of coasting or drop-out, or the filtered sync that
excludes extraneous syncs not occurring within the
sync filter window.
Table 46. SOGOUT Polarity Settings
SOGOUT Select Function
00 Raw SOG from sync slicer (SOG0 or SOG1)
01 Raw Hsync (Hsync0 or Hsync1)
10 Regenerated sync from sync filter
11 Hsync to PLL
The power-up default setting is 11.
0x24 0 Output Clock Invert
This bit allows inversion of the output clock as
specified by Register 0x25, Bits 7 to 6. The power-up
default setting is 0.
Table 47. Output Clock Invert
Select Result
0 Noninverted clock
1 Inverted clock
0x25 7-6 Output Clock Select
These bits select the clock output on the DATACLK
pin. They include 1/2× clock, a 2× clock, a 90° phase
shifted clock or the normal pixel clock. The power-up
default setting is 01.
These two bits select the drive strength for all the
high-speed digital outputs (except VSOUT, A0 and
O/E field). Higher drive strength results in faster
rise/fall times and in general makes it easier to capture
data. Lower drive strength results in slower rise/fall
ti mes and helps to reduce EMI and digitally generated power
supply noise. The power-up default setting is 11.
Table 49. Output Drive Strength
Output Drive Result
00 Low output drive strength
01 Medium low output drive strength
10 Medium high output drive strength
11 High output drive strength
0x25 3-2 Output Mode
These bits choose between four options for the output
mode, one of which is exclusive to an HDMI input.
4:4:4 mode is standard RGB; 4:2:2 mode is YCrCb,
which reduces the number of active output pins from
24 to 16; 4:4:4 double data rate (DDR) output mode;
and the data is RGB mode, but changes on every clock
edge. The power-up default setting is 00.
Table 50. Output Mode
Output
Mode Result
00 4:4:4 RGB mode
01 4:2:2 YCrCb mode + DDR 4:2:2 on blue (secondary)
10
11 12-bit 4:2:2 (HDMI option only)
DDR 4:4:4: DDR mode + DDR 4:2:2 on blue
econdary)
(s
The power-up default is 00.
0x25 1 Primary Output Enable
This bit places the primary output in active or high
impedance mode.
The primary output is designated when using either
4:2:2 o
r DDR 4:4:4. In these modes, the data on the
red and green output channels is the primary output,
while the output data on the blue channel (DDR
YCrCb) is the secondary output. The power-up
default setting is 1.
Table 51. Primary Output Enable
Select Result
0 Primary output is in high impedance mode
1 Primary output is enabled
0x25 0 Secondary Output Enable
This bit places the secondary output in active or high
impedance mode.
The secondary output is designated when using either
r DDR 4:4:4. In these modes the data on the
4:2:2 o
blue output channel is the secondary output while the
output data on the red and green channels is the
primary output. Secondary output is always a DDR
YCrCb data mode. The power-up default setting is 0.
Table 52. Secondary Output Enable
Select Result
0 Secondary output is in high impedance mode
1 Secondary output is enabled
0x26 7 Output Three-State
When enabled, this bit puts all outputs (except
SOGOUT) in a high impedance state. The power-up
default setting is 0.
Table 53. Output Three-State
Select Result
0 Normal outputs
1 All outputs (except SOGOUT) in high impedance mode
0x26 6 SOG Three-State
When enabled, this bit allows the SOGOUT pin to be
placed in a high impedance state. The power-up
default setting is 0.
Table 54. SOGout Three-State
Select Result
0 Normal SOG output
1 SOGOUT pin is in high impedance mode
0x26 5 SPDIF Three-State
When enabled, this bit places the SPDIF audio output
pins in a high impedance state. The power-up default
setting is 0.
Table 55. SOGOUT Three-State
Select Result
0 Normal SPDIF output
1 SPDIF pins in high impedance mode
0x26 4 I2S Three-State
When enabled, this bit places the I2S output pins in a
high impedance state. The power-up default setting
is 0.
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Table 56. SOGOUT Three-State
Select Result
0 Normal I2S output
1 I2S pins in high impedance mode.
0x26 3 Power-Down Polarity
This bit defines the polarity of the input power-down
pin. The power-up default setting is 1.
Table 57. Power-Down Input Polarity
Select Result
0 Power-down pin is active low
1 Power-down pin is active high
0x26 2-1 Power-Down Pin Function
These bits define the different operational modes of
the power-down pin. These bits are functional only
when the power-down pin is active; when it is not
active, the part is powered up and functioning. The
power-up default setting is 00.
Table 58. Power Down Pin Function
PWRDN
Pin
Functio n
00
01
10
11
0x26 0 Power-Down
Table 59. Power-Down Settings
Select Result
0 Normal operation
1 Power-Down
0x27 7 Auto Power-Down Enable
Result
The chip is powered down and all outputs except
SOGOUT ar
The chip is powered down and all outputs are in
high impedanc
The chip remains powered up, but all outputs
cept SOGOUT are in high impedance mode.
ex
The chip remains powered up, but all outputs are
in high impeda
This bit is used to put the chip in power-down mode.
In this mode the chips power dissipation is reduced to
a fraction of the typical power (see Tab l e 1 for exact
power dissipation). When in power-down, the
HSOUT, VSOUT, DATACK, and all 30 of the data
outputs are put into a high impedance state. Note that
the SOGOUT output is not put into high impedance.
Circuit blocks that continue to be active during
power-down include the voltage references, sync
processing, sync detection, and the serial register.
These blocks facilitate a fast start-up from powerdown. The power-up default setting is 0.
This bit enables the chip to go into low power mode,
or seek mode if no sync inputs are detected. The
power-up default setting is 1.
e in high impedance mode.
e mode.
nce mode.
Table 60. Auto Power-Down Select
Auto
Power Down Result
0 Auto power down disabled
1 Chip powers down if no sync inputs present
0x27 6 HDCP A0 Address
This bit sets the LSB of the address of the HDCP I2C.
This should be set to 1 only for a second receiver in a
dual-link configuration. The power-up default is 0.
0x27 5 MCLK External Enable
This bit enables the MCLK to be supplied externally. If
an external MCLK is used, then it must be locked to
the video clock according to the CTS and N available
2
in the I
and the input MCLK results in dropped or repeated
audio samples. The power-up default setting is 0.
Table 61. MCLK External Select
Select Result
0 Use internally generated MCLK
1 Use external MCLK input
C. Any mismatch between the internal MCLK
BT656 GENERATION
0x27 4 BT656 Enable
This bit enables the output to be BT656-compatible
with defined start of active video (SAV) and end of
active video (EAV) controls to be inserted. These
require specification of the number of active lines,
active pixels per line, and delays to place these
markers. The power-up default setting is 0.
Table 62. BT656 Mode
Select Result
0 Disable BT656 video mode
1 Enable BT656 video mode
0x27 3 Force DE Generation
This bit allows the use of the internal DE generator in
DVI mode. The power-up default setting is 0.
Table 63. DE Generation
Select Result
0 Internal DE generation disabled
1 Force DE generation via programmed registers
0x27 2-0 Interlace Offset
These bits define the offset in Hsyncs from Field 0 to
Field 1. The power-up default setting is 000.
0x28 7-2 Vsync Delay
These bits set the delay (in lines) from the leading
edge of Vsync to active video. The power-up default
setting is 24.
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0x28 1-0 Hsync Delay MSBs
Along with the eight bits following these ten bits set
the delay (in pixels) from the Hsync leading edge to
the start of active video. The power-up default setting
is 0x104.
0x29 7-0 Hsync Delay LSBs
See the Hsync Delay MSBs section.
0x2A 3-0 Line Width MSBs
Along with the 8 bits following these 12 bits, set the
width of the active video line (in pixels). The powerup default setting is 0x500.
0x2B 7-0 Line Width LSBs
See the line width MSBs section.
Table 66. Detected TMDS Sync Results
Detect Result
0 No TMDS DE present
1 TMDS DE detected
0x2F 5 TMDS Active
This read only bit indicates the presence of a TMDS
clock.
Table 67. Detected TMDS Clock Results
Detect Result
0
1 TMDS clock detected
No TMDS clock present
0x2F 4 AV Mute
This read-only bit indicates the presence of AV (audio
video) mute based on general control packets.
0x2C 3-0 Screen Height MSBs
Along with the 8 bits following these 12 bits, set the
height of the active screen (in lines). The power-up
default setting is 0x2D0.
0x2D 7-0 Screen Height LSBs
See the Screen Height MSBs section.
0x2E 7 Ctrl Enable
When set, this bit allows Ctrl [3:0] signals decoded
from the DVI to be output on the I2S data pins. The
power-up default setting is 0.
Table 64. CTRL Enable.
Select Result
0 I2S signals on I2S lines
1 Ctrl [3:0] output on I2S lines
0x2E 6-5 I2S Output Mode
These bits select between four options for the I2S
output: I2S, right-justified, left-justified, or raw
IEC60958 mode. The power-up default setting is 00.
These bits set the I2S bit width for right-justified
mode. The power-up default setting is 24 bits.
0x2F 6 TMDS Sync Detect
This read-only bit indicates the presence of a TMDS
DE.
Table 68. Detected AV Mute Status
Detect Result
0 AV not muted
AV muted
0x2F 3 HDCP Keys Read
This read-only bit reports if the HDCP keys were read
successfully.
Table 69. HDCP Keys
Detect Result
0 Failure to read HDCP keys
1 HDCP keys read
0x2F 2-0 HDMI Quality
These read-only bits indicate a level of HDMI quality
based on the DE (display enable) edges. A larger
number indicates a higher quality.
0x30 6 HDMI Content Encrypted
This read-only bit is high when HDCP decryption is
in use (content is protected). The signal goes low
when HDCP is not being used. Customers can use this
bit to determine whether or not to allow copying of
the content. The bit should be sampled at regular
intervals since it can change on a frame by frame
basis.
Table 70. HDCP Activity
Detect Result
0 HDCP not in use
1 HDCP decryption in use
0x30 5 DVI Hsync Polarity
This read-only bit indicates the polarity of the DVI
Hsync.
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Table 71. DVI Hsync Polarity Detect
Detect Result
0 DVI Hsync polarity is low active
1 DVI Hsync polarity is high active
0x30 4 DVI Vsync Polarity
This read-only bit indicates the polarity of the DVI
Vsync.
Table 72. DVI Vsync Polarity Detect
Detect Result
0 DVI Vsync polarity is low active
1 DVI Vsync polarity is high active
0x30 3-0 HDMI Pixel Repetition
These read-only bits indicate the pixel repetition on
DVI. 0 = 1×, 1 = 2×, 2 = 3×, up to a maximum
repetition of 10× (0x9).
These bits set the pseudo sync pulse width maximum
for Macrovision detection in pixel clocks. This is
functional for 13.5 MHz SDTV or 27 MHz progressive
scan. Power up default is 9.
0x31 3-0 Macrovision Pulse Min
These bits set the pseudo sync pulse width maximum
for Macrovision detection in pixel clocks. This is
functional for 13.5 MHz SDTV or 27 MHz progressive
scan. Power up default is 6.
0x32 7 Macrovision Oversample Enable
Tells the Macrovision detection engine whether we are
oversampling or not. This accommodates 27 MHz
sampling for SDTV and 54 MHz sampling for
progressive scan and is used as a correction factor for
clock counts. Power up default is 0.
0x32 6 Macrovision PAL Enable
Tells the Macrovision detection engine to enter PAL
mode when set to 1. Default is 0 for NTSC mode.
0x32 5-0 Macrovision Line Count Start
Sets the start line for Macrovision detection. Along
with Register 0x33, Bits [5:0] they define the region
where MV pulses are expected to occur. The power-up
default is Line 13.
0x33 7 Macrovision Detect Mode
0 = standard definition
1 = progressive scan mode
0x33 6 Macrovision Settings Override
This defines whether preset values are used for the
MV line counts and pulse widths or the values stored
2
C registers.
in I
0 = use hard coded settings for line counts and pulse
dths
wi
1 = use I
2
C values for these settings
0x33 5-0 Macrovision Line Count End
Sets the end line for Macrovision detection. Along
with Register 0x32, Bits [5:0] they define the region
where MV pulses are expected to occur. The power up
default is Line 21.
0x34 7-6 Macrovision Pulse Limit Select
Sets the number of pulses required in the last three
lines (SD mode only). If there is not at least this
number of MV pulses, the engine stops. These two
bits define the following pulse counts:
00 = 6
01 = 4
10 = 5 (defa
11 = 7
ult)
0x34 5 Low Frequency Mode
Sets whether the audio PLL is in low frequency mode
or not. Low frequency mode should only be set for
pixel clocks < 80 MHz.
0x34 4 Low Frequency Override
Allows the previous bit to be used to set low frequency
mode rather than the internal autodetect.
The default power up values for the color space converter coefficients (R0x35 through R0x4C) are set for
ATSC RGB to YCbCr conversion. They are completely
programmable for other conversions.
0x34 1 Color space Converter Enable
This bit enables the color space converter. The powerup default setting is 0.
Table 74. Color space Converter
Select Result
0 Disable color space converter
1 Enable color space converter
0x35 6-5 Color space Converter Mode
These two bits set the fixed point position of the CSC
coefficients, including the A4, B4, and C4 offsets.
Table 75. CSC Fixed Point Converter Mode
Select Result
00 ±1.0, −4096 to 4095
01 ±2.0, −8192 to 8190
1× ±4.0, −16384 to 16380
0x35 4-0 Color space Conversion Coefficient A1 MSBs
These 5 bits form the 5 MSBs of the Color space
Conversion Coefficient A1. This combined with the
8 LSBs of the following register form a 13-bit twos
complement coefficient which is user programmable.
The equation takes the form of:
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
R
OUT
G
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
OUT
B
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
The default value for the 13 bit A1 coefficient is
0x0C52.
0x36 7-0 Color space Conversion Coefficient A1 LSBs
See the Register 0x35 section.
0x37 4-0 CSC A2 MSBs
These five bits form the 5 MSBs of the Color space
Conversion Coefficient A2. Combined with the 8
LSBs of the following register they form a 13 bit twos
complement coefficient that is user programmable.
The equation takes the form of:
= (A1 × RIN) + (A2 × GIN) + (A3 × BIN) + A4
R
OUT
= (B1 × RIN) + (B2 × GIN) + (B3 × BIN) + B4
G
OUT
B
= (C1 × RIN) + (C2 × GIN) + (C3 × BIN) + C4
OUT
The default value for the 13-bit A2 coefficient is
0x0800.
These bits control the division of the MCLK out of the
PLL.
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Table 76.
PLL_N [2:0] MCLK Divide Value
0 /1
1 /2
2 /3
3 /4
4 /5
5 /6
6 /7
7 /8
0x58 3 N_CTS_Disable
This bit makes it possible to prevent the N/CTS packet
on the link from writing to the N and CTS registers.
0x58 2-0 MCLK fs_N
These bits control the multiple of 128 fs used for
MCLK out.
Table 77.
MCLK fs_N [2:0] fs Multiple
0 128
1 256
2 384
3 512
4 640
5 768
6 896
7 1024
0x59 6 MDA/MCL PU Disable
This bit disables the inter MDA/MCL pull-ups.
0x59 5 CLK Term O/R
This bit allows for overriding during power down.
0 = auto, 1 = manual.
0x59 4 Manual CLK Term
This bit allows normal clock termination or
disconnects this. 0 = normal, 1 = disconnected.
0x59 2 FIFO Reset UF
This bit resets the audio FIFO if underflow is detected.
0x59 1 FIFO Reset OF
This bit resets the audio FIFO if overflow is detected.
0x59 0 MDA/MCL Three-State
This bit three-states the MDA/MCL lines to allow incircuit programming of the EEPROM.
0x5A 6-0 Packet Detect
This register indicates if a data packet in specific
sections has been detected. These seven bits are
updated if any specific packet has been received since
last reset or loss of clock detect. Normal is 0x00.
0x5E 7-6 Channel Status Mode
0x5E 5-3 PCM Audio Data
0x5E 2 Copyright Information
0x5E 1 Linear PCM Identification
0x5E 0 Use of Channel Status Block
0x5F 7-0 Channel Status Category Code
0x60 7-4 Channel Number
0x60 3-0 Source Number
0x61 5-4 Clock Accuracy
0x61 3-0 Sampling Frequency
These are the most significant 8 bits of a 20-bit word
used in the 20-bit N term in the regeneration of the
audio clock.
These are the most significant 4 bits of a 20-bit word
used along with the 20-bit CTS term to regenerate the
audio clock.
This register indicates whether data is RGB, 4:4:4 or
4:2:2.
Rev. 0 | Page 50 of 64
AD9880
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Table 80.
Y Video Data
00 RGB
01 YCbCr 4:2:2
10 YCbCr 4:4:4
0x81 4 Active Format Information Present
0 = no data
1 = active format information valid
0x81 3-2 Bar Information
Table 81.
B Bar Type
00 No bar information
01 Horizontal bar information valid
10 Vertical bar information valid
11 Horizontal and vertical bar information valid
0x81 1-0 Scan Information
Table 82.
S [1:0] Scan Type
00 No information
01 Overscanned (television)
10 Underscanned (computer)
0x82 7-6 Colorimetry
Table 83.
C [1:0] Colorimetry
00 No data
01 SMPTE 170M, ITU601
10 ITU 709
0x82 5-4 Picture Aspect Ratio
Table 84.
M[1:0] Aspect Ratio
00 No data
01 4:3
10 16:9
0x82 3-0 Active Format Aspect Ratio
Table 85.
R [3:0] Active Format A/R
0x8 Same as picture aspect ratio (M [1:0])
0x9 4:3 (center)
0xA 16:9 (center)
0xB 14:9 (center)
0x83 1-0 Nonuniform Picture Scaling
Table 86.
SC [1:0] Picture Scaling
00 No known nonuniform scaling
01 Has been scaled horizontally
10 Has been scaled vertically
11 Has been scaled both horizontally and vertically
0x84 6-0 Video ID Code
See CEA EDID short video descriptors.
0x85 3-0 Pixel Repeat
This value indicates how many times the pixel was
repeated. 0x0 = no repeats, sent once, 0x8 = 8 repeats,
sent 9 times, and so on.
0x86 7-0 Active Line Start LSB
Combined with the MSB in Register 0x88, these bits
indicate the beginning line of active video. All lines
before this comprise a top horizontal bar. This is used
in letter box modes. If the 2-byte value is 0x00, there is
no horizontal bar.
0x87 6-0 New Data Flags (NDF)
This register indicates whether data in specific
sections has changed. In the address space from 0x80
to 0xFF, each register address ending in 0b111 (for
example, 0x87, 0x8F, 0x97, 0xAF) is an NDF register.
They all have the same data and all are reset upon
reading any one of them.
Combined with the MSB in Register 0x8A these bits
indicate the last line of active video. All lines past this
comprise a lower horizontal bar. This is used in letterbox modes. If the 2-byte value is greater than the
number of lines in the display, there is no lower
horizontal bar.
0x8A 7-0 Active Line End MSB
See Register 0x89.
0x8B 7-0 Active Pixel Start LSB
Combined with the MSB in Register 0x8C, these bits
indicate the first pixel in the display which is active
video. All pixels before this comprise a left vertical bar.
If the 2-byte value is 0x00, there is no left bar.
0x8C 7-0 Active Pixel Start MSB
See Register 0x8B.
Rev. 0 | Page 51 of 64
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0x8D 7-0 Active Pixel End LSB
Combined with the MSB in Register 0x8E these bits
indicate the last active video pixel in the display. All
pixels past this comprise a right vertical bar. If the
2-byte value is greater than the number of pixels in the
display, there is no vertical bar.
0x8E 7-0 Active Pixel End MSB
See Register 0x8D.
0x8F 6-0 NDF
See Register 0x87.
0x90 7-0 Audio Infoframe Version
0x91 7-4 Audio Coding Type
These bits identify the audio coding so that the
receiver may process audio properly.
0x92 4-2 Sampling Frequency
0x92 1-0 Ample Size
0x93 7-0 Max Bit Rate
For compressed audio only when this value is
multiplied by 8 kHz represents the maximum bit rate.
A value of 0x08 in this field would yield a maximum
bit rate of (8 kHz × 8 kHz = 64 kHz).
0x94 7-0 Speaker Mapping
These bits define the mapping (suggested placement)
of speakers.
Table 90.
Abbreviation Speaker Placement
FL Front left
FC Front center
FR Front right
FCL Front center left
FCR Front center right
RL Rear left
RC Rear center
RR Rear right
RCL Rear center left
RCR Rear center right
LFE Low frequency effect
Rev. 0 | Page 52 of 64
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Table 91.
CA Channel Number
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1
These bits define the amount of attenuation. The value
directly corresponds to the amount of attenuation: for
example, 0000 = 0 dB, 0001 = 1 dB to 1111 = 15 dB
attenuation.
0x96 7-0 Reserved
0x97 6-0 New Data Flags
See Register 0x87 for a description.
Rev. 0 | Page 53 of 64
0x98 7-0 Source Product Description (SPD)
Infoframe Version
0x99 7-0 Vender Name Character 1 (VN1)
This is the first character in eight that is the name of
the company that appears on the product. The data
characters are 7-bit ASCII code.
0x9A 7-0 VN2
0x9B 7-0 VN3
0x9C 7-0 VN4
0x9D 7-0 VN5
0x9E 7-0 VN6
0x9F 6-0 New Data Flags
0xC8 7 International Standard Recording Code
(ISRC1) Continued
This bit indicates that a continuation of the 16 ISRC1
packet bytes (an ISRC2 packet) is being transmitted.
0xC8 6 ISRC1 Valid
This bit is an indication of the whether ISRC1 packet
bytes are valid.
Rev. 0 | Page 54 of 64
AD9880
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Table 96.
ISRC1 Valid Description
0 ISRC1 status bits and PBs not valid
1 ISRC1 status bits and PBs valid
0xC8 2-0 ISRC Status
These bits define where in the ISRC track the samples
are: at least two transmissions of 001 occur at the
beginning of the track, while in the middle of the
track, continuous transmission of 010 occurs followed
by at least two transmissions of 100 near the end of the
track.
A 2-wire serial interface control interface is provided in the
AD9880. Up to two AD9880 devices can be connected to the
2-wire serial interface, with a unique address for each device.
The 2-wire serial interface comprises a clock (SCL) and a
idirectional data (SDA) pin. The analog flat panel interface
b
acts as a slave for receiving and transmitting data over the serial
interface. When the serial interface is not active, the logic levels
on SCL and SDA are pulled high by external pull-up resistors.
Data received or transmitted on the SDA line must be stable for
e duration of the positive-going SCL pulse. Data on SDA must
th
change only when SCL is low. If SDA changes state while SCL is
high, the serial interface interprets that action as a start or stop
sequence.
There are six components to serial bus operation:
•St
art signal
•Sla
ve address byte
•B
ase register address byte
•Da
ta byte to read or write
• Stop
• Ac
When the serial interface is inactive (SCL and SDA are high)
co
signal is a high-to-low transition on SDA while SCL is high.
This signal alerts all slaved devices that a data transfer sequence
is coming.
The first eight bits of data transferred after a start signal
co
single R/W\ bit (the eighth bit). The R/W\ bit indicates the
direction of data transfer, read from (1) or write to (0) the slave
device. If the transmitted slave address matches the address of
the device (set by the state of the SA0 input pin as shown in
Tabl e 97 ), the AD9880 acknowledges by bringing SDA low on
the 9th SCL pulse. If the addresses do not match, the AD9880
does not acknowledge.
Table 97. Serial Port Addresses
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1
A6 (MSB) A
1 0 0 1 1 0 0
signal
knowledge (Ack)
mmunications are initiated by sending a start signal. The start
mprise a seven bit slave address (the first seven bits) and a
A
5
A
4
A
3
A
2
A
1
0
Data Transfer via Serial Interface
For each byte of data read or written, the MSB is the first bit of
the sequence.
If the AD9880 does not acknowledge the master device during a
ite sequence, the SDA remains high so the master can gener-
wr
ate a stop signal. If the master device does not acknowledge the
AD9880 during a read sequence, the AD9880 interprets this as
end of data. The SDA remains high, so the master can generate
a stop signal.
Writing data to specific control registers of the AD9880 requires
t
hat the 8-bit address of the control register of interest be written after the slave address has been established. This control
register address is the base address for subsequent write operations. The base address auto-increments by one for each byte of
data written after the data byte intended for the base address. If
more bytes are transferred than there are available addresses,
the address does not increment and remains at its maximum
value. Any base address higher than the maximum value does
not produce an acknowledge signal.
Data are read from the control registers of the AD9880 in a
simi
lar manner. Reading requires two data transfer operations:
The base address must be written with the R/W bit of the slave
addr
ess byte low to set up a sequential read operation.
Reading (the R/
the previously established base address. The address of the read
register auto-increments after each byte is transferred.
To terminate a read/write sequence to the AD9880, a stop signal
m
ust be sent. A stop signal comprises a low-to-high transition
of SDA while SCL is high.
A repeated start signal occurs when the master device driving
he serial interface generates a start signal without first genera-
t
ting a stop signal to terminate the current communication. This
is used to change the mode of communication (read, write)
between the slave and master without releasing the serial
interface lines.
bit of the slave address byte high) begins at
W
Rev. 0 | Page 56 of 64
AD9880
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SDA
t
SCL
t
STAH
BUFF
t
DHO
t
DAL
t
DSU
t
DAH
Figure 17. Serial Port Read/Write Timing
t
STASU
t
STOSU
05087-007
Serial Interface Read/Write Examples
Write to one control register:
art signal
• St
• Sla
ve address byte (R/W\ bit = low)
ase address byte
• B
• Da
ta byte to base address
•Stop
signal
Write to four consecutive control registers:
art signal
• St
• Sla
ve address byte (R/W\ bit = LOW)
•B
ase address byte
•Da
ta byte to base address
•D
ata byte to (base address + 1)
•D
ata byte to (base address + 2)
•D
ata byte to (base address + 3)
•Stop
signal
Read from one control register:
art signal
•St
ve address byte (R/W\ bit = low)
•Sla
ase address byte
•B
art signal
•St
ve address byte (R/W\ bit = high)
•Sla
ta byte from base address
• Da
• Stop
signal
Read from four consecutive control registers:
art signal
•St
ve address byte (R/W\ bit = low)
•Sla
ase address byte
•B
art signal
•St
ve address byte (R/W\ bit = high)
•Sla
ta byte from base address
•Da
ata byte from (base address + 1)
•D
ata byte from (base address + 2)
•D
ata byte from (base address + 3)
• D
• Stop
signal
BIT 7
SCL
Figure 18. Serial Interface—Typical Byte Transfer
ACKBIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0SDA
Rev. 0 | Page 57 of 64
05087-008
AD9880
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PCB LAYOUT RECOMMENDATIONS
The AD9880 is a high-precision, high-speed analog device. To
achieve the maximum performance from the part, it is important to have a well laid-out board. The following is a guide for
designing a board using the AD9880.
Analog Interface Inputs
Using the following layout techniques on the graphics inputs is
extremely important:
•M
inimize the trace length running into the graphics
inputs. This is accomplished by placing the AD9880 as
close as possible to the graphics VGA connector. Long
input trace lengths are undesirable, because they pick up
more noise from the board and other external sources.
The bypass capacitors should be physically located between the
p
ower 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 capacitor pads down to the power
plane is generally the best approach.
It is particularly important to maintain low noise and good
st
ability of PV
in PV
can result in similarly abrupt changes in sampling clock
DD
phase and frequency. This can be avoided by careful attention to
regulation, filtering, and bypassing. It is highly desirable to
provide separate regulated supplies for each of the analog
circuitry groups (V
(the clock generator supply). Abrupt changes
DD
and PVDD).
D
• Place
• U
The AD9880 has very high input bandwidth (300 MHz). While
t
his is desirable for acquiring a high resolution PC graphics
signal with fast edges, it means that it also captures any high
frequency noise present. Therefore, it is important to reduce the
amount of noise that gets coupled to the inputs. Avoid running
any digital traces near the analog inputs.
Due to the high bandwidth of the AD9880, sometimes low-pass
f
iltering the analog inputs can help to reduce noise. For many
applications, filtering is unnecessary. Experiments have shown
that placing a series ferrite bead prior to the 75 Ω termination
resistor is helpful in filtering out excess noise. Specifically, the
part used was the Fair-Rite 2508051217Z0, but each application
may work best with a different bead value. Alternatively, placing
a 100 Ω to 120 Ω resistor between the 75 Ω termination resistor
and the input coupling capacitor can also be beneficial.
the 75 Ω termination resistors (see Figure 3) as close
to the AD9880 chip as possible. Any additional trace length
between the termination resistors and the input of the
AD9880 increases the magnitude of reflections, which
corrupts the graphics signal.
se 75 Ω matched impedance traces. Trace impedances
other than 75 Ω also increase the chance of reflections.
Power Supply Bypassing
It is recommended to bypass each power supply pin with a
0.1 µF capacitor. The exception is in the case where two or more
supply pins are adjacent to each other. For these groupings of
powers/grounds, it is only necessary to have one bypass
capacitor. The fundamental idea is to have a bypass 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
AD9880, since that interposes resistive vias in the path.
Some graphic controllers use substantially different levels of
ower when active (during active picture time) and when idle
p
(during Hsync and Vsync 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 PV
source (for example, from a 12 V supply).
It is recommended to use a single ground plane for the entire
rd. Experience has repeatedly shown that the noise perfor-
boa
mance is the same or better with a single ground plane. Using
multiple ground planes can be detrimental since each separate
ground plane is smaller and long ground loops can result.
In some cases, using separate ground planes is unavoidable. For
hose cases, it is recommend to place a single ground plane
t
under the AD9880. The location of the split should be at the
receiver of the digital outputs. In 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 is power plane to
AD9880 to digital output trace to digital data receiver to digital
ground plane to analog ground plane .
, from a different, cleaner, power
DD
PLL
Place the PLL loop filter components as close as possible to the
FILT pin.
Do not place any digital or other high frequency traces near
t
hese components.
Use the values suggested in the datasheet with 10% tolerances
less.
or
Rev. 0 | Page 58 of 64
AD9880
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Outputs (Both Data and Clocks)
Try to minimize the trace length that the digital outputs have to
drive. Longer traces have higher capacitance, which require
more current that causes more internal digital noise.
Shorter traces reduce the possibility of reflections.
Adding a series resistor of value 50 Ω to 200 Ω can suppress
eflections, reduce EMI, and reduce the current spikes inside of
r
the AD9880. If series resistors are used, place them as close as
possible to the AD9880 pins (although try not to add vias or
extra length to the output trace to move the resistors closer).
If possible, limit the capacitance that each of the digital outputs
ives to less than 10 pF. This can be easily accomplished by
dr
keeping traces short and by connecting the outputs to only one
device. Loading the outputs with excessive capacitance increases
the current transients inside of the AD9880 and creates more
digital noise on its power supplies.
Digital Inputs
The digital inputs on the AD9880 were designed to work with
3.3 V signals, but are tolerant of 5.0 V signals. Therefore, no
extra components need to be added if using 5.0 V logic.
Any noise that enters the Hsync input trace can add jitter to the
tem. Therefore, minimize the trace length and do not run
sys
any digital or other high frequency traces near it.
Rev. 0 | Page 59 of 64
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COLOR SPACE CONVERTER (CSC) COMMON SETTINGS
Table 98. HDTV YCrCb (0 to 255) to RGB (0 to 255) (Default Setting for AD9880)