PRODUCT SPECIFICATION
TMC22091/TMC22191
Mask Register
A Mask Register is provided which is logically ANDed with
incoming color-index data to facilitate pixel animation and
other special graphics effects. The Mask Register is ahead of
the Data Key comparators and is enabled only when color-
index input is selected. Mask Register programming and
operation are similar to that of the 171/176 family of graph-
ics RAMDACS.
Colorspace Conversion Matrix and
Interpolator
The matrix converts RGB data (whether from RGB inputs or
color-indexed CLUT data) into Y, B-Y, R-Y format for
encoding. In input configurations where the pixel input is
already in Y, B-Y, R-Y format, the matrix is bypassed. When
pixel data is input in YC
B
C
R
422 format, the interpolation fil-
ters produce YC
B
C
R
444 for encoding.
Color Lookup Table
The Color Lookup Table (CLUT) is a 256 x 8 x 3 random-
access memory. It provides means for offset, gain, gamma,
and color correction in RGB and YC
B
C
R
operating modes. It
provides a full 24-bit color lookup function for color-index
mode. It can be loaded in the same manner as a standard
VGA RAMDAC.
Sync Generator
The TMC22x91 can operate in Master, Genlock, or Slave
modes. In Master and Genlock modes, the encoder internally
generates all timing and sync signals, and provides Horizon-
tal Sync, Vertical Sync, and Pixel Data Control (PDC) to the
external frame buffer circuitry. PDC is independently select-
able to function as an input or an output. In Genlock mode,
the TMC22x91 timing is controlled by the TMC22071 Gen-
locking Video Digitizer over the CVBS
7-0
bus, GVSYNC,
and GHSYNC. The encoder, in turn, produces VHSYNC,
VVSYNC, and PDC for the frame buffer interface.
MODE
GBR444
MSB
23
G
7
16 15
8
7
LSB
0
Format Control Register
MSB
LSB
G
R
Y
Y
G
0
B7
B
G
C
B
C
B/
C
R
B
0
R
7
R
B
C
R
R
0
00011000
RGB444
R
7
Y
7
R
0
G
7
Y
0
C
B7
C
B7
Y
0
C
R7
G
0
B
7
C
B0
R
R7
C
B0
C
R0
B
0
R
R0
00010000
YCBCR444
00011100
YCBCR422
Y
7
00011101
COLOR INDEX
P
7
Pixel
B
0
R
4
P
0
0001X011
GBR15
G
4
G
R
G
0
B
4
B
G
R
B
R
0
00011010
RGB15
R
4
R
0
G
4
G
0
B
4
B
0
24300A
00010010
Figure 1a. Pixel Data Format
3
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
