Datasheet

Confidential for truly Only
11.03.2009 PRELIMINARY SPECIFICATION proprietary to OmniVision Technologies
4-9
For the average-based AEC/AGC algorithm, the measured window is horizontally and vertically adjustable and divided
by sixteen (4x4) zones (see figure 4-5). Each zone (or block) is 1/16th of the image and has a 4-bit weight in calculating
the average luminance (YAVG). The final YAVG is the weighted average of the sixteen zones. The 4-bit weight could be
n/16 where n is from 0 to 15.
table 4-6 average based control function registers
address register name
default
value R/W description
0x3A0F WPT 0x78 RW
Bit[7:0]: WPT
Stable range high limit (enter)
0x3A10 BPT 0x68 RW
Bit[7:0]: BPT
Stable range low limit (enter)
0x3A11 HIGH VPT 0xD0 RW
Bit[7:0]: vpt_high
Fast zone high limit when step ratio
auto mode is disabled
0x3A1B WPT2 0x78 RW
Bit[7:0]: wpt2
Stable range high limit
(from stable state to unstable state)
0x3A1E BPT2 0x68 RW
Bit[7:0]: bpt2
Stable range low limit
(from stable state to unstable state)
0x3A1F LOW VPT 0x40 RW
Bit[7:0]: vpt_low
Fast zone low limit when step ratio
auto mode is disabled