Datasheet

ADV7342/ADV7343 Data Sheet
Rev. | Page 58 of 108
The SD CSC matrix scalar uses the following equations:
Y = (a1 × R) + (a2 × G) + (a3 × B) + a4
Pr = (b1 × R) + (b2 × G) + (b3 × B) + b4
Pb = (c1 × R) + (c2 × G) + (c3 × B) + c4
The coefficients and their default values and register locations
are shown in Table 48.
Table 48. SD Manual CSC Matrix Default Values
Coefficient Subaddress Default
a1 0xBD 0x42
a2 0xBE 0x81
a3 0xBF 0x19
a4 0xC0 0x10
b1 0xC1 0x70
b2 0xC2 0x5E
b3 0xC3 0x12
b4 0xC4 0x80
c1 0xC5 0x26
c2 0xC6 0x4A
c3
0xC7
0x70
c4 0xC8 0x80
ED/HD Manual CSC Matrix Adjust Feature
The ED/HD manual CSC matrix adjust feature provides custom
coefficient manipulation for color space conversions and is used
in ED and HD modes only. The ED/HD manual CSC matrix
adjust feature can be enabled using Subaddress 0x02, Bit 3.
Normally, there is no need to enable this feature because the CSC
matrix automatically performs the color space conversion based
on the input mode chosen (ED or HD) and the input and output
color spaces selected (see Table 47). For this reason, the ED/HD
manual CSC matrix adjust feature is disabled by default.
If RGB output is selected, the ED/HD CSC matrix scalar uses
the following equations:
R = GY × Y + RV × Pr
G = GY × Y − (GU × Pb) − (GV × Pr)
B = GY × Y + BU × Pb
Note that subtractions are implemented in hardware.
If YPrPb output is selected, the following equations are used:
Y = GY × Y
Pr = RV × Pr
Pb = BU × Pb
where:
GY = Subaddress 0x05, Bits[7:0] and Subaddress 0x03, Bits[1:0].
GU = Subaddress 0x06, Bits[7:0] and Subaddress 0x04, Bits[7:6].
GV = Subaddress 0x07, Bits[7:0] and Subaddress 0x04, Bits[5:4].
BU = Subaddress 0x08, Bits[7:0] and Subaddress 0x04, Bits[3:2].
RV = Subaddress 0x09, Bits[7:0] and Subaddress 0x04, Bits[1:0].
On power-up, the CSC matrix is programmed with the default
values shown in Table 49.
Table 49. ED/HD Manual CSC Matrix Default Values
Subaddress Default
0x03 0x03
0x04 0xF0
0x05 0x4E
0x06 0x0E
0x07 0x24
0x08 0x92
0x09 0x7C
When the ED/HD manual CSC matrix adjust feature is enabled,
the default coefficient values in Subaddress 0x03 to Subaddress
0x09 are correct for the HD color space only. The color
components are converted according to the following 1080i and
720p standards (SMPTE 274M, SMPTE 296M):
R = Y + 1.575Pr
G = Y − 0.468Pr − 0.187Pb
B = Y + 1.855Pb
The conversion coefficients should be multiplied by 315 before
being written to the ED/HD CSC matrix registers This is
reflected in the default values for GY = 0x13B, GU = 0x03B,
GV = 0x093, BU = 0x248, and RV = 0x1F0.
If the ED/HD manual CSC matrix adjust feature is enabled and
another input standard (such as ED) is used, the scale values for
GY, GU, GV, BU, and RV must be adjusted according to this
input standard color space. The user should consider that the
color component conversion may use different scale values.
For example, SMPTE 293M uses the following conversion:
R = Y + 1.402Pr
G = Y – 0.714Pr – 0.344Pb
B = Y + 1.773Pb
The programmable CSC matrix is used for external ED/HD
pixel data and is not functional when internal test patterns are
enabled.
Programming the CSC Matrix
If custom manipulation of the ED/HD CSC matrix coefficients
is required for a YCrCb-to-RGB color space conversion, use the
following procedure:
1. Enable the ED/HD manual CSC matrix adjust feature
(Subaddress 0x02, Bit 3).
2. Set the output to RGB (Subaddress 0x02, Bit 5).
3. Disable sync on PrPb (Subaddress 0x35, Bit 2).
4. Enable sync on RGB (optional) (Subaddress 0x02, Bit 4).
The GY value controls the green signal output level, the BU
value controls the blue signal output level, and the RV value
controls the red signal output level.
D