AR0833 Datasheet, PDF (32/64 Pages) ON Semiconductor – 8 Mp CMOS Digital Image Sensor

AR0833: 1/3.2-Inch 8 Mp CMOS Digital Image Sensor
Integration Time for Interlaced HDR Readout
13. If the above bits are not set to 1, then examine otpm_status register R0x304E[9] to ver-
ify if the OTPM memory is full and 0x304E[10] to verify if OTPM memory is insuffi-
cient.
14. Remove the high voltage (VPP) and float VPP pin.
Reading the OTPM
1. Apply power to all the power rails of the sensor (VDD_IO, VAA, VAA_PIX, DVDD_1V2,
DVDD_1V2_PHY, and DVDD_1V8) at their nominal voltage.
2. Set EXTCLK to normal operating frequency.
3. Perform proper reset sequence to the sensor.
4. Set R0x3134=0xCD95 (Timing Configuration)
5. Set R0x304C[15:8] = Record Type (for example, 0x30)
6. Set R0x304C[7:0] = Length of the record which is the number of data registers to be
read back. This could be set to 0 during OTPM auto read if length is unknown.
7. Set R0x3054 = 0x0400
8. Initiate the auto read sequence by setting the otpm_control_auto_read_start bit
(R0x304A[4]) = 1.
9. Poll the otpm_control_auto_rd_end bit (R0x304A[5]) to determine when the sensor is
finished reading the word(s). When this bit becomes 1, the otpm_control_auto_rd_-
success bit (R0x304A[6]) will indicate whether the memory was read successfully or
not.
10. Data can now be read back from the otpm_data registers (R0x3800-R0x39FE).
Image Acquisition Modes
The AR0833 supports two image acquisition modes:
1. Electronic rolling shutter (ERS) mode.
This is the normal mode of operation. When the AR0833 is streaming, it generates
frames at a fixed rate, and each frame is integrated (exposed) using the ERS. When the
ERS is in use, timing and control logic within the sensor sequences through the rows
of the array, resetting and then reading each row in turn. In the time interval between
resetting a row and subsequently reading that row, the pixels in the row integrate inci-
dent light. The integration (exposure) time is controlled by varying the time between
row reset and row readout. For each row in a frame, the time between row reset and
row readout is fixed, leading to a uniform integration time across the frame. When the
integration time is changed (by using the two-wire serial interface to change register
settings), the timing and control logic controls the transition from old to new integra-
tion time in such a way that the stream of output frames from the AR0833 switches
cleanly from the old integration time to the new while only generating frames with
uniform integration. See “Changes to Integration Time” on page 24.
2. Global reset release (GRR) mode.
This mode can be used to acquire a single image at the current resolution. In this
mode, the end point of the pixel integration time is controlled by an external electro-
mechanical shutter, and the AR0833 provides control signals to interface to that shut-
ter. The operation of this mode is described in detail in “Global Reset Release (GRR)”
on page 46.
The benefit for the use of an external electromechanical shutter is that it eliminates the
visual artifacts associated with ERS operation. Visual artifacts arise in ERS operation,
particularly at low frame rates, because an ERS image effectively integrates each row of
the pixel array at a different point in time.
AR0833_DS Rev. H Pub. 4/15 EN
32
©Semiconductor Components Industries, LLC, 2015.