ov7620 OmniVision Technologies, Inc, ov7620 Datasheet - Page 27

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

OV7620/OV7120 Product Specifications - Rev. 1.2 (7/10/01)
0.11 SCCB REGISTER SETS
OV7620/OV7120 can be configured, by setting pin CS<2:0> high or low at reset/power up, to one
of eight slave IDs as listed below, the ID can not be altered once the chip is out of reset or power
up state.
OV7620/OV7120 support two option: single chip and multiple chip decided by PIN MID. If MID
set to LOW (Default value), chip slave ID is 42(for write) and 43(for read). If MID set to HIGH,
OV7620/OV7120 can support 8 slave ID selection. Default MID is LOW by internal setting.
In write cycle, the second byte in SCCB bus is the subaddress for selecting the individual on chip
registers, the third byte is the data associated with this register. Writing to unimplemented sub-
address and reserved subaddress is ignored.
In read cycle, the second byte is the data associated with the previous stored subaddress. read-
ing of unimplemented subaddress returns unknown.
Registers [00] ~ [02] contains image effect parameters that also can be modified by internal con-
trols in auto adjust mode. This provides a simple way to read out those parameters computed by
chip internal controls. To do this, first set the chip in auto adjust mode (Register 13 bit 0=1, reg-
ister 12 bit 2 = 1, register 12 bit 5=1), wait for the image is stable, the register [00],[01] and [02]
will be updated by internal control circuit. Then returns it to manual adjust mode(register 13 bit
0=0), all the registers retain the last adjusted values and can be read or overwritten by external
host. When the chip is operated in auto adjust mode(register 13 bit 0=1), register [00] ~ [02] will
be update by internal algorithm and if write data to them, there will be no effect on chip parame-
ters. The register data can be read out.
The detailed definitions of each register are described below.
Register 00 - rw: AGC gain control
WRITE ID (hex)
Bits
Default
READ ID (hex)
CS<2:0>
AGC<5:0> - gain setting for the entire image channel.
Null
-
000
The formula is:
Gain = (AGC<3:0>/16+1)*(AGC<4>+1)*(AGC<5>+1); range (1x ~ 7.75x), AGC<5> and
AGC<4> control SA2.
42
43
AGC6
-
001
46
47
AGC5
Table 1.10: Slave ID
0
010
4a
4b
AGC4
0
011
4e
4f
Preliminary
AGC3
0
100
52
53
AGC2
0
Company Confidential
OMNIVISION TECHNOLOGIES INC.
101
56
57
AGC1
0
110
5a
5b
AGC0
0
111
5e
5f