adv7322 Analog Devices, Inc., adv7322 Datasheet - Page 51

• Manufacturer Part Number: adv7322
• Description: Multiformat 11-bit Hdtv Video Encoder
• Manufacturer: Analog Devices, Inc.

Preliminary Technical Data
This is reflected in the preprogrammed values for GY = 0x138B,
GU = 0x93, GV = 0x3B, BU = 0x248, and RV = 0x1F0.
Again if RGB matrix is enabled and another input standard is
used (SD or PS), the scale values for GY, GU, GV, BU, and RV
must be adjusted according to this input standard color space.
The user should consider the fact that the color component
conversion might use different scale values. For example,
SMPTE 293M uses the following conversion:
The manual RGB matrix adjust feature can be used to control
the HD output levels in cases where the video output does not
conform to the standard due to altering the DAC output stages
such as termination resistors. The programmable RGB matrix is
used for external HD/PS data and is not functional when
internal test patterns are enabled.
Adjusting Registers 0x05 to 0x09 requires the manual RGB
matrix adjust to be enabled [Register 0x02, Bit 3 =1].
Programming the RGB Matrix
If custom manipulation of coefficients is required, The RGB
matrix is enabled in Address 0x02, Bit 3. The output should be
set to RGB [Address 0x02, Bit 5], sync on PrPb should be
disabled (default) [Address 0x15, Bit 2], and sync on RGB is
optional [Address 0x02, Bit 4].
GY at Addresses 0x03 and 0x05 control the green signal output
levels. BU at Addresses 0x04 and 0x08 control the blue signal
output levels, and RV at Addresses 0x04 and 0x09 control the
red signal output levels. To control YPrPb output levels, YUV
output should be enabled [Address 0x02, Bit 5]. In this case GY
[Address 0x05; Address 0x03, Bits 0 and 1] is used for the Y
output, RV [Address 0x09; Address 0x04, Bits 0 and 1] is used
for the Pr output, and BU [Address 0x08; Address 0x04, Bits 2
and 3] is used for the Pb output.
If RGB output is selected, the RGB matrix scaler uses the
following equations:
If YPrPb output is selected, the following equations are used:
R = Y + 1.402 Pr
G = Y – 0.714 Pr – 0.344 Pb
B = Y + 1.773 Pb
G = GY × Y + GU × Pb + GV × Pr
B = GY × Y + BU × Pb
R = GY × Y + RV × Pr
Y = GY × Y
U = BU × Pb
V = RV × Pr
Rev. PrA | Page 51 of 88
Upon power-up, the RGB matrix is programmed with the
default values in Table 31.
Table 31. RGB Matrix Default Values
Address
0x03
0x04
0x05
0x06
0x07
0x08
0x09
When the manual RGB matrix adjust feature is not enabled, the
ADV7322 automatically scales YCrCb inputs to all standards
supported by this part as selected by input mode Register 0x01
[6:4].
SD Luma and Color Control
[Subaddresses 0x5C, 0x5D, 0x 5E, 0x 5F]
SD Y Scale, SD Cr Scale, and SD Cb Scale are three 10-bit-wide
control registers that scale the Y, Cb, and Cr output levels.
Each of these registers represents the value required to scale the
Cb or Cr level from 0.0 to 2.0 and the 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,
Address 0x5D, SD Y Scale Register = 0xA6
Address 0x5E, SD Cb Scale Register = 0xA6
Address 0x5F, SD Cr Scale Register = 0xA6
Note that this feature affects all interlaced output signals, i.e.,
CVBS, Y-C, YPrPb, and RGB.
SD Hue Adjust Value
[Subaddress 0x60]
The hue adjust value is used to adjust the hue on the composite
and chroma outputs.
These eight bits represent the value required to vary the hue of
the video data, i.e., the variance in phase of the subcarrier
during active video with respect to the phase of the subcarrier
during the color burst. The ADV7322 provides a range of ±22.5°
Address 0x5C, SD LSB Register = 0x15
Y, Cr, or Cb Scalar Value = Scale Factor × 512
Scale Factor = 1.18
Y, Cb, or Cr Scale Value = 1.18 × 512 = 665.6
Y, Cb, or Cr Scale Value = 665 (rounded to the nearest
Y, Cb, or Cr Scale Value = 1010 0110 01b
integer)
Default
0x03
0xF0
0x4E
0x0E
0x24
0x92
0x7C
ADV7322