Datasheet

ADV7320/ADV7321

Rev. A | Page 52 of 88

SD Brightness Detect

[Subaddress 0x7A]

The ADV7320/ADV7321 allow monitoring the brightness level

of the incoming video data. Brightness detect is a read-only

Double Buffering

[Subaddress 0x13, Bit 7; Subaddress 0x48, Bit 2]

Double-buffered registers are updated once per field upon the

falling edge of the Vsync signal. Double buffering improves the

overall performance because modifications to register settings

are not made during active video, but take effect upon the start

of the active video.

Double buffering can be activated on the following HD

registers: HD Gamma Curve A, HD Gamma Curve B, and HD

CGMS registers.

Double buffering can be activated on the following SD registers:

SD Gamma Curve A and SD Gamma Curve B, SD Y scale, SD U

scale, SD V scale, SD brightness, SD closed captioning, and SD

Macrovision Bits 5 to 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

05067-069

Figure 69. Examples of Brightness Control Values