PRODUCT SPECIFICATION
TMC2193
Gamma Correction
Control Registers for this section
Address
0x04
0x04
0x04
0x04
Bit(s)
7
6
5
4
Name
GAMENG
GAMENC
GAMSELG
GAMSELC
Color Space Matrix
Control Registers for this section
Address
0x30
0x31
0x32
0x33
0x34
0x35
0x36
0x37
0x38
0x39
0x3A
0x3A
0x3B
0x3B
0x3C
0x3C
for 0
≤
X
≤
255
for 0
≤
X
≤
6
for 7
≤
X
≤
255
0x3D
0x3D
0x3E
0x3E
0x3F
0x3F
Bit(s)
7-0
7-0
7-0
7-0
7-0
7-0
7-0
7-0
7-0
7-0
7-4
3-0
7-4
2-0
7-4
2-0
7-4
3-0
7-4
3-0
2
1-0
Name
MCF1L
MCF2L
MCF3L
MCF4L
MCF5L
MCF6L
MCF7L
MCF8L
MCF9L
MCF10L
MCF1M
MCF2M
MCF3M
MCF4M
MCF5M
MCF6M
MCF7M
MCF8M
MCF9M
MCF10M
NMEH
CSMFMT
Inherent in all CRT displays is a non-linearity between the
voltage applied to the electron guns and the CRT phosphor
brightness. Traditionally this non-linearity, gamma, is com-
pensated at the camera. However, many sources today are
mixed in the digital domain and do not contain any gamma
correction.
For this reason the TMC2193 contains optional gamma cor-
rection process. The TMC2193 contains two independent
gamma circuits, one for the Green data path and the other for
the Blue and Red data path. Each gamma processor has two
(2) gamma compensation curves, one for NTSC and one for
PAL, that can be applied to the incoming video data.
The formulas for the gamma curves are:
PAL:
Y=X
NTSC: Y = 4.5 * X
Y = 1.099 * X
1/2.22
– 0.099
1024
PAL Gamma Curve
896
RGB Outputs (0 to 1023)
1/2.8
768
640
512
384
NTSC Gamma Curve
128
0
0
32
64
96
128
160
192
224
RGB Inputs (0 to 255)
65-6294-08
256
256
The color space matrix (CSM) has four modes of operation,
which are controlled by CSMFMT. The CSMFMT bits con-
figures the color space matrix to produce the desired outputs
from the input source. The inputs for the CSM can be either
RGB or YC
B
C
R
. In all four modes YUV for the composite
generation will always be one set of component outputs of
the CSM. The other set of components outputs can be either
RGB or YP
B
P
R
.
•
CSMFMT = 00 , YC
B
C
R
input source with YUV and
YP
B
P
R
outputs.
Matrix configuration:
Y
composite
U
V
Y
component
P
B
P
R
= MCF1 * Y
in
= MCF4 * C
B
= MCF6 * C
R
= MCF8 * Y
in
= MCF9 * C
B
= MCF10 * C
R
Figure 7. Gamma Curves
REV. 1.0 3/26/03
9
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
