5.0 Control Register Definitions-Function 0
Fusion 878A
5.3 Local Registers (Memory Mapped)
PCI Video Decoder
5-16
Conexant
100600B
0x034—Chroma (U) Gain Register, Lower Byte (SAT_U_LO)
Upon reset SAT_U_LO is initialized to 0xFE. SAT_U_LO(0) is the LSB. SAT_U_MSB in the Miscellaneous
CONTROL register, and SAT_U_LO concatenate to create a 9-bit register (SAT_U). Use this register to add a
gain adjustment to the U component of the video signal. By adjusting the U and V color components of the
video stream the same amount, you adjust the saturation. For normal saturation adjustment, the gain in both the
color difference paths must be the same (i.e. the ratio between the value in the U gain register and the value in
the V gain register should be kept constant at the default power-up ratio). When changing the saturation, if the
SAT_U_MSB bit is altered, take care to ensure that the other bits in the CONTROL register are not affected.
Table 5-3. (SAT SAT_U_LO)
Bits
Type
Default
Name
Description
[7:0]
RW
0xFE
SAT_U_LO
This register is used to add a gain adjustment to the U component of
the video signal. By adjusting the U and V color components of the
video stream by the same incremental value, you can adjust the
saturation.
Decimal Value
Hex Value
Percent of Original Signal
511
0x1FF
201.18 %
510
0x1FE
200.79 %
.
.
.
.
.
.
255
0x0FF
100.39 %
254
0x0FE
100.00 %
.
.
.
.
.
.
128
0x080
50.39 %
.
.
.
.
.
.
1
0x001
0.39 %
0
0x000
0.00 %