PRODUCT SPECIFICATION
TMC22x5yA
Y Offset
Decoder Output
CCIR 601 Spec
The 8 bit Y offset adds any offset required in the Y or RGB
data outputs. For example 64 (16) for the 64 (16) to 940
Color
Red
Y
C
C
Y
C
C
R
B
R
B
325 -150 447 326 -151 448
(235) 10 bit (8 bit) 601 outputs. When the output is YC C
B R
this offset is applied to the luminance data only. TheY offset
also provides the blanking level for RGB
outputs with syncs.
Blue
163 448
64
-73
0
164
64
448 -72
Black
0
0
0
PAL digital composite input and RGB (0-1023) outputs:
Matrix Limiters
The different limiters are listed below, 10 bit data is
assumed.
Color
White
Yellow
Cyan
Y
U
0
V
0
572
507
401
336
236
171
65
-250
84
57
Table 13. Matrix Limiters
-352
-295
295
352
-57
0
LMT
1-0
Comments
Green
Magenta
Red
-165
165
-84
250
0
00
01
RGB output format, limited from 0 to 1023
YC C output format, Y limited from 0 to
B
R
1023 and C C limited to +/- 511.
B
R
10
11
RGB output format, limited from 64 to 940
YC C output format, Y limited from 64 to
Blue
B
R
Black
0
940 and C C limited to +/- 448
B
R
The nominal scaling factors are simply:
YGx = 1023/572 = 1 + (202/256)
Examples of Output Matrix Operation
From the SMPTE-170M specification:
UGx = (1023/572)*(1/0.492) = 3 + (163/256)
VGx = (1023/572)*(1/0.877) = 2 + (10/256)
YOFF= 0
PED = 0
Color
White
Yellow
Cyan
Y
U
0
V
0
584
523
423
361
267
205
105
44
-236
79
54
Color
White
Yellow
Cyan
G
1023
1023
1023
1023
0
R
1023
1023
0
B
1023
0
-332
-278
278
332
-54
0
Green
Magenta
Red
-156
156
-79
236
0
1023
1
Green
Magenta
Red
0
Blue
1023
1023
0
1022
1
Black
0
Blue
0
1023
0
YC C data ranges are:
B R
Black
0
0
Y data range is 64 to 940 (876)
C C data ranges are 64 to 960 (+/- 448)
B R
It is also possible with the architecture supplied to use the
limiters on the output of the matrix to clip the output video
deliberately by using a slightly larger gain than is required.
The Y_Offset can achieve the same by setting its value to be
one lsb less than the minimum clip level.
Matrix programming:
YGx = (876 / 540) = 1 + (159/256)
UGx = (448 / 236) = 1 + (230/256)
VGx = (448 / 332) = 1 + (89/256)
YOFF = 64
Buffer Registers
PED = 44
The BUFFER pin allows the user to externally switch
between two sets of internal registers that have the same
function. This register buffering allows the matrix gain,
picture hue, and luma offset to be changed at a known time
relative to the input data.
Decoder Output
CCIR 601 Spec
Color
White
Yellow
Cyan
Y
C
C
Y
C
B
C
R
B
R
939
0
0
940
0
0
Registers 17 to 1D are selected when the BUFFER pin is
LOW and registers 27 to 2D are selected when the BUFFER
841 -448
73
840 -448
72
pin is HIGH. If the msb of the decoder product code DPC is
678 150 -447 678 151 -448
578 -296 -376 578 -296 -375
2
LOW, an 8 bit decoder has been selected and the bottom 2
bits of registers 17 to 1A and 27 to 2A are forced to zero.
Green
Magenta 426 296 376 426 296 375
REV. 1.0.0 2/4/03
57
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
