OV6620 Datasheet, PDF (28/31 Pages) List of Unclassifed Manufacturers – SINGLE-CHIP CMOS CIF COLOR DIGITAL CAMERA

OMNIVISION TECHNOLOGIES, Inc.
Advanced Information
Preliminary
OV6620/OV6120
SINGLE IC CMOS COLOR AND B/W DIGITAL CAMERAS
Subad-
dress
(hex)
Register
20
COME
21
YOFF
22
UOFF
23
REFC
24
AEW
25
AEB
Default
(hex)
Read/
Write
Descriptions
Common Control E
COME[7] - HREF pixel number selection. “1” - HREF include 704 PCLK, every data output
twice.
COME[6] - reserved.
COME[5] - “1” First stage aperture correction enable. Correction strength will be decided by
register [07]. “0” disable first stage aperture correction.
COME[4] - “1” Second stage aperture correction enable. Correction strength and threshold
value will be decided by COMF[7] ~ COMF[4].
COME[3] - AWB smart mode enable. 1 - Drop out pixel when compare pixel red, blue and
green component level to change register [01] and [02], which luminance level is higher than
presetting level and lower than presetting level, this two level is set by register [0F].
00
RW
0 - calculate all pixels to get AWB result. Valid only when COMB[0]=1 and COMA[2]=1
COME[2] - AWB stop when field/frame image average luminance level is lower than a
presetting level enable. 1 - enable stop AWB when image luminance level is low. 0 - AWB is
independent with field/frame luminance level. Valid only when COMB0=1 and COMA[2]=1.
Average compare level is set by GAM[7:5].
COME[1] - AWB fast/slow mode selection. “1” - AWB is always fast mode, that is register [01]
and [02] is changed every field/frame. “0” AWB is slow mode, [01] and [02] change every 16/
64 field/frame decided by COMK[1]. When AWB enable, COMA[2]=1, AWB is working as
fast mode at first 1024 field/frame, than as slow mode later.
COME[0] - Digital output driver capability increase selection: “1” Double digital output driver
current; “0” low output driver current status.
Y Channel Offset Adjustment
YOFF[7] - Offset adjustment direction 0 - Add Y[6:0]; 1 -Substrate Y[6:0].
YOFF[6:0] -Y channel digital output offset adjustment. Range: +127mV ~ -127mV. If
80
RW
COMG[2]=0, this register will be updated by internal auto A/D BLC circuit, and write a value
to this register with I²C has no effect. If COMG[2]=1, Y channel offset adjustment will use
the register stored value which can be changed by I²C. If COMF[1]=0, this register has no
adjustment effect to A/D output data. If output RGB raw data, this register will adjust R/G/B
data.
U Channel Offset Adjustment
UOFF[7]: - Offset adjustment direction: 0 - Add U[6:0]; 1 -Substrate U[6:0].
UOFF[6:0] - U channel digital output offset adjustment. Range: +128mV ~ -128mV. If
80
RW
COMG[2]=0, this register will be updated by internal auto A/D BLC circuit, and write a value
to this register with I²C has no effect. If COMG[2]=1, U channel offset adjustment will use
the register stored value which can be changed by I²C. If COMF[1]=1, this register has no
effect to A/D output data. If output RGB raw data, this register will adjust R/G/B data.
Reference Control
04
RW
REFC[7:6] - Select different crystal circuit power level (11 = minimum).
REFC[5:4] - reserved
REFC[3:0]: Reference Voltage range selection. 2.5V - 3.5V and step is 0.0625V.
Automatic Exposure Control: Bright Pixel Ratio Adjustment
AEW[7:0] - Used as calculate bright pixel ratio. OV6620 AEC algorithm is count whole field/
frame bright pixel (its luminance level is higher than a fixed level) and black pixel (its
luminance level is lower than a fixed level) number. When bright/black pixel ratio is same as
the ratio defined by register [25] and [26], image stable. This register is used to define bright
33
RW
pixel ratio, default is 25%, each LSB represent step: 1.3% Change range is: [01] ~ [CA];
Increase AEW[7:0] will increase bright pixel ratio. For same light condition, the image
brightness will increase if AEW[7:0] increase.
Note: AEW[7:0] must combine with register [26] AEB[7:0]. The relation must be as
follows:
AEW[7:0] + AEB[7:0] > [CA].
Automatic Exposure Control: Black Pixel Ration Adjustment
AEB[7:0] - used as calculate black pixel ratio. OV6620 AEC algorithm is count whole field/
frame bright pixel (its luminance level is higher than a fixed level) and black pixel (its
luminance level is lower than a fixed level) number. When bright/black pixel ratio is same as
the ratio defined by register [25] and [26], image stable. This register is used to define black
97
RW
pixel ratio, default is 75%, each LSB represent step: 1.3%; Change range is: [01] ~ [CA];
Increase AEB[7:0] will increase black pixel ratio. For same light condition, the image
brightness will decrease if AEB[7:0] increase.
Note: AEB[7:0] must e combined with register [25] AEW[7:0]. The relation must be as
follows: EW[7:0] + AEB[7:0] > [CA].
28
Version 1.11
14 May 1999