UG-707
ADV8005 Hardware Reference Manual
Table 76: Sample Brightness Control Values
1
Setup Level (NTSC) with Pedestal
Setup Level (NTSC) Without Pedestal
Setup Level (PAL)
Brightness Control Value
(
22.5 IRE
15 IRE
15 IRE
0x1E
15 IRE
7.5 IRE
7.5 IRE
0x0F
7.5 IRE
0 IRE
0 IRE
0x00
0 IRE
−7.5 IRE
−7.5 IRE
0x71
1
Values in the range of 0x3F to 0x44 may result in an invalid output signal.
Figure 118: Examples of Brightness Control Values
7.4.15.
Double Buffering
Double buffered registers are updated once per field. Double buffering improves overall performance because modifications to register settings
are not made during active video but take effect prior to the start of the active video on the next field. This can be enabled for both SD and
ED/HD using
and
7.4.15.1.
ED/HD Doubling Buffering
db_en_hdtv
, Encoder Map,
Address 0xE433[7]
This bit is used to enable the double buffering on the appropriate ED/HD registers.
Function
db_en_hdtv
Description
0 (default)
Cb after falling edge of HSYNC
1
Cr after falling edge of HSYNC
Double buffering can be activated on the following ED/HD functions: the ED/HD gamma A and gamma B curves and the ED/HD CGMS
registers.
7.4.15.2.
SD Doubling Buffering
db_en
, Encoder Map,
Address 0xE488[2]
This bit is used to enable double buffering on the appropriate SD registers.
Function
db_en
Description
1
Enabled
0 (default)
Disabled
Double buffering can be activated on the following SD functions: the SD gamma A and gamma B curves, SD Y scale, SD Cr scale, SD Cb scale,
SD brightness, SD closed captioning, and SD Macrovision bits (Reg 0xE4E0, Bits [5:0]).
NTSC WITHOUT PEDESTAL
NO SETUP
VALUE ADDED
POSITIVE SETUP
VALUE ADDED
100 IRE
0 IRE
NEGATIVE SETUP
VALUE ADDED
–7.5 IRE
+7.5 IRE
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