ADV8005 Hardware Reference Manual
UG-707
hue[7:0]
, Encoder Map,
Address 0xE4A0[7:0]
This register is used to set the SD hue adjust value.
Function
hue[7:0]
Description
0x00 (default)
SD Hue Value
7.4.13.
SD Brightness Detect
encoder core allows the user to monitor the brightness level of the incoming video data. This feature is used to monitor the
average brightness of the incoming Y signal on a field-by-field basis. The information is read from the I
2
C and, based on this information, the
color saturation, contrast, and brightness controls can be adjusted, for example, to compensate for very dark pictures.
The luma data is monitored in the active video area only. The average brightness I
2
C register is updated on the falling edge of every VSYNC
signal. This can be monitored using
bright_detect_val[7:0]
, Encoder Map,
Address 0xE4BA[7:0] (Read Only)
This register is used to adjust the SD brightness value.
Function
bright_detect_val[7:0]
Description
0xXX
(Larger settings results in a brighter output)
7.4.14.
SD Brightness Control
When this feature is enabled, the SD brightness/WSS control register,
, is used to control brightness by adding a programmable setup
level onto the scaled Y data. To enable this feature,
setup_en
, Encoder Map,
Address 0xE487[3]
This bit is used to enable the SD brightness control feature.
Function
setup_en
Description
1
Enabled
0 (default)
Disabled
For NTSC with pedestal, the setup can vary from 0 IRE to 22.5 IRE. For NTSC without pedestal and for PAL, the setup can vary from −7.5 IRE to
+15 IRE. Refer to
for more details.
The SD brightness control register is an 8-bit register. The seven LSBs of this 8-bit register are used to control the brightness level, which can be
a positive or negative value.
For example, to add a +20 IRE brightness level to an NTSC signal with pedestal, the procedure is as follows:
0 × (SD Brightness Value) =
0 × (IRE Value × 2.015631) =
0 × (20 × 2.015631) = 0 × (40.31262) ≈ 0x28
To add a –7 IRE brightness level to a PAL signal, write 0x72 to
0 × (SD Brightness Value) =
0 × (IRE Value × 2.075631) =
0 × (7 × 2.015631) = 0x(14.109417) ≈ 0001110b
0001110b into twos complement = 1110010b = 0x72
setup[6:0]
, Encoder Map,
Address 0xE4A1[6:0]
This signal is used to specify the SD brightness value.
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