adv7314 Analog Devices, Inc., adv7314 Datasheet - Page 46

• Manufacturer Part Number: adv7314
• Description: Multiformat 216 Mhz Video Encoder With Six Nsv 14-bit Dacs
• Manufacturer: Analog Devices, Inc.

ADV7314
COLOR CONTROLS AND RGB MATRIX
HD/PS Y Level, Cr Level, Cb Level
[Subaddress 16h–18h]
Three 8-bit registers at Address 16h, 17h, 18h are used to program
the output color of the internal HD test pattern generator, whether
it is the lines of the cross hatch pattern or the uniform field test
pattern. They are not functional as color controls on external
pixel data input. For this purpose, the RGB matrix is used.
The standard used for the values for Y and the color difference
signals to obtain white, black, and the saturated primary and
complementary colors conforms to the ITU-R BT.601–4 standard.
Table VIII shows sample color values to be programmed into
the color registers when Output Standard Selection is set to
EIA 770.2.
Sample
Color
White
Black
Red
Green
Blue
Yellow
Cyan
Magenta
HD RGB Matrix
[Subaddress 03h–09h]
When the programmable RGB matrix is disabled [Address 02h,
Bit 3], the internal RGB matrix takes care of all YCrCb to YUV
or RGB scaling according to the input standard programmed
into the device.
When the programmable RGB matrix is enabled, the color
components are converted according to the 1080i standard
[SMPTE 274M]:
This is reflected in the preprogrammed values for GY = 138Bh,
GU = 93h, GV = 3B, BU = 248h, RV = 1F0.
If another input standard is used, the scale values for GY, GU,
GV, BU, and RV have to be adjusted according to this input
standard. The user must consider that the color component
conversion might use different scale values. For example,
SMPTE 293M uses the following conversion:
The programmable RGB matrix can be used to control the HD
output levels in cases where the video output does not conform
to standard due to altering the DAC output stages such as ter-
mination resistors. The programmable RGB matrix is used for
external HD data and is not functional when the HD test pattern
is enabled.
Y' = 0.2126R' + 0.7152 G' + 0.0722 B'
CR' = [0.5/(1 – 0.0722)] (B'–Y')
CR' = [0.5/(1 – 0.2126)] (R'–Y')
Table VIII. Sample Color Values for
EIA770.2 Output Standard Selection
Y' = 0.299 R' + 0.587 G' + 0.114 B'
CB' = [0.5 / (1 – 0.114)] (B'–Y')
CR' = [0.5 / (1 – 0.299)] (R'–Y')
Color Y
Value
235 (EB)
16 (10)
81 (51)
145 (91)
41 (29)
210 (D2)
170 (AA)
106 (6A)
Color CR
Value
128 (80)
128(80)
240 (F0)
34 (22)
110 (6E)
146 (92)
16 (10)
222 (DE)
Color CB
Value
128 (80)
128 (80)
90 (5A)
54 (36)
240 (F0)
16 (10)
166 (A6)
202 (CA)
–46–
Programming the RGB Matrix
The RGB matrix should be enabled [Address 02h, Bit 3], the
output should be set to RGB [Address 02h, Bit 5], sync on
PrPb should be disabled [Address 15h, Bit 2], sync on RGB is
optional [Address 02h, Bit 4].
GY at Addresses 03h and 05h control the output levels on the
green signal, BU at 04h and 08h control the blue signal output
levels, and RV at 04h and 09h control the red output levels. To
control YPrPb output levels, YUV output should be enabled
[Address 02h, Bit 5]. In this case GY [Address 05h; Address 03,
Bit 0–1] is used for the Y output, RV [Address 09; Address 04,
Bit 0–1] is used for the Pr output and BU [Address 08h; Address
04h, Bit 2–3] is used for the Pb output.
If RGB output is selected the RGB matrix scaler uses the fol-
lowing equations:
If YUV output is selected the following equations are used:
On power-up, the RGB matrix is programmed with default values:
When the programmable RGB matrix is not enabled, the
ADV7314 automatically scales YCrCb inputs to all standards
supported by this part.
SD Luma and Color Control
[Subaddresses 5Ch, 5Dh, 5Eh, 5Fh]
SD Y scale, SD Cr scale, and SD Cb scale are 10-bit control
registers to scale the Y, U, and V output levels.
Each of these registers represents the value required to scale the
U or V level from 0.0 to 2.0 and Y level from 0.0 to 1.5 of its
initial level. The value of these 10 bits is calculated using the
following equation:
For example:
Scale Factor = 1.18
Address 5Ch, SD LSB Register = 15h
Address 5Dh, SD Y Scale Register = A6h
Address 5Eh, SD V Scale Register = A6h
Address 5Fh, SD U Scale Register = A6h
Y, U, or V Scale Value = 1.18
Y, U, or V Scale Value = 665 (rounded to the nearest integer)
Y, U, or V Scale Value = 1010 0110 01b
Y, U, or V Scalar Value = Scale Factor
Table IX. RGB Matrix Default Values
G = GY
B = GY
R = GY
Address
03h
04h
05h
06h
07h
08h
09h
Y + GU
Y + BU
Y + RV
U = BU
V = RV
Y = GY
512 = 665.6
Pr
Pb
Pb + GV
Pb
Pr
Default
03h
F0h
4Eh
0Eh
24h
92h
7Ch
Y
Pr
512
REV. 0