ov7620 OmniVision Technologies, Inc, ov7620 Datasheet - Page 10

• Manufacturer Part Number: ov7620
• Description: Single-chip Cmos Vga Color Digital Camera
• Manufacturer: OmniVision Technologies, Inc

Preliminary
Company Confidential
OV7620/OV7120 Product Specifications - Rev. 1.2 (7/10/01)
OMNIVISION TECHNOLOGIES INC.
To decrease data transfer rate while high resolution image unnecessary, OV7620/OV7120 pro-
vides a solution, that is it can output QVGA resolution image. This mode decrease pixel rate one
half. The resolution default value is 320x240 and can be programmable. Every line only output
one half data. For Interlaced Mode, all field line output (320), for Progressive Scan Mode, only
one half line data output.
The digital video port also offer RGB Raw Data 16 Bit/8 Bit format. The output sequence is
matched to OV7620/OV7120 Color Filter Pattern, that is UV channel output sequence is G R G
R ..., Y Channel output sequence is B G B G,....To 8 Bit RGB Raw data output format, just use
Y channel and disable UV channel, output sequence is B G R G ....
OV7620/OV7120 supports CCIR656 YCrCb 4:2:2 digital output format. The SAV(Start of Active
Video) and EAV(End of Active Video) is just at the beginning and the end of HREF window. So
the position of SAV and EAV is changing with active pixel window. Also you can get 8 bit RGB
raw data with SAV and EAV information.
OV7620/OV7120 support some flexible YUV output format. One is standard YUV 4:2:2. Another
is U V sequence swap format, that means UV channel output V U V U ...(16 Bit) and V Y U Y ...(8
Bit). The 3rd format is Y/UV sequence swap in 8 Bit output, that is Y U Y V ....
OV7620/OV7120 can be use as black&white camera. At this mode, it’s vertical resolution will
be higher than color mode. All data will be output from Y port and UV port will be tri-state. Data
(Y/RGB) output rate is same as 16 Bit mode.
OV7620/OV7120 can be programmable to swap Y/UV or RGB output byte MSB and LSB. Y7 -
Y0 default sequence is Y7 is MSB and Y0 is LSB. When swap, Y7 is LSB and Y0 is MSB, relative
middle bits are swapped.
An important factor about digital camera is how convenient the interface is, OV7620/OV7120 has
made the frame rate programmable and the A/D synchronous to the actual pixel rate. Essentially,
it is a whole image capture system in a single chip. Since the internal AEC has a range of 1:260,
and AGC have 24dB, for the most of applications, the camera can adjust itself to meet the lighting
condition without user intervention.
OV7620/OV7120 support hardware/software RESET function: when RESET pin tie to high,
whole chip will be reset including all register. Hardware sleeping mode: when PWDN tie to high,
chip clock will be stop and internal circuit reset except all SCCB register. Also there is a SCCB
control software reset control register 12 bit 7, which is same as hardware RESET pin function.
OV7620/OV7120 hardware reset time minimum is 1 ms.
OV7620/OV7120 support hardware/software power saving mode. When the PWDN pin tie to
high, whole chip will be set to power down status without any current consumption. For software
power down control, all current set to zero except crystal circuit. In power down mode, all SCCB
register value will be kept.
Two control mechanism have been built into OV7620/OV7120: A. one time read-in of pin states
at power up or RESET status, including hardware and software reset; B. SCCB interface. Two
methods are mutually exclusive, only one is used at a time, selected by pin
. Method A has
SBB
limited access to full chip features.
The power up reset method is a one time setting, the setting can not be altered later. The pins