BT848 ETC, BT848 Datasheet - Page 133

• Manufacturer Part Number: BT848
• Description: Single-Chip Video Capture for PCI
• Manufacturer: ETC

Bt848/848A/849A
Single-Chip Video Capture for PCI
Chroma (U) Gain Register, Lower Byte
Memory Mapped Location 0x034 – (SAT_U_LO)
This is the alternate definition for the SAT_U_LO register when using the Bt848A/849A.
digital video mode).
adjustments as in analog video decode operation.
Brooktree
Bits
[7:0]
Upon reset it is initialized to 0xFE (this must be changed to 0x80 to get standard chroma (U) gain values when in
The SAT_U register when used in digital video input mode requires different programming to get the same U gain
Type
RW
®
SAT_U_LO
Default
0xFE
Name
SAT_U_LO
NOTE:
Decimal Value
511
510
.
.
181
180
.
.
128
.
.
1
0
The standard 100% settings are also different for SECAM vs NTSC or
PAL.
C
L848A_A
ONTROL
Description
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, the saturation is
adjusted.
Hex Value
0x1FF
0x1FE
.
.
0x0B5
0x0B4
.
.
0x080
.
.
0x001
0x000
R
EGISTER
D
IGITAL
V
IDEO
Chroma (U) Gain Register, Lower Byte
I
N
S
UPPORT
% of Original Signal
399.22%
398.43%
.
.
141.41%
140.63%
.
.
100%
.
.
0.78%
0.00%
(B
T
848A/849A O
123
NLY
)