A920:
Camera
Description
The Conexant imager allows15 fps(frames per second) image readouts at VGA resolution. The Conexant imager will output raw Bayer RGB 8-bit/pixel data to the
Conexant backend processor (U7600).
The Conexant backend processor will receive the Bayer RGB data from the imager and process the image data into 8-bit YUV uncompressed or compressed data that is
send through the VODATA bus to the Helen application processor. U7600 can process the YUV data in VGA(640x480), QVGA(320x240), CIF(352x288), and
QCIF(176x144) output resolutions. Control functions for U7600 are done through a 2-wire serial interface(SSCLK and SSDA).
The QCIF qualifier logic devices(U7602 and U7603) are used for viewfinder and video capture functions. VSYNC and HSYNC signals provide vertical and horizontal
synchronization of the image signals. VSYNC indicates a start and end of a valid video frame while HSYNC indicated the start and end of a valid video line.
VODATA sends 8-bit processed image data in YUV 4:2:2 format to the Helen processor. VODATA3 is shared by the camera and IrDA devices. Due to the hardware
restrictions, Camera and IrDA wouldn‘t work simultaneously. For this reason, IRDA_SHUTDOWN is used to enable VODATA3 during camera operation.
CAM_ROT_DETECT is used to indicate the rotated position of the imager. A magnet integrated in the Conexant imager will activate the Hall effect switch and cause a
state change for CAM_ROT_DETECT. The Helen will respond with a horizontal inversion of the image.
The image that Helen receives goes through a DSP pre-processing stage where the YUV 4:2:2 is converted to YUV 4:2:0. To display the image on the unit’s display, the
YUV 4:2:0 signal passes through a DSP post-processing stage and converts it to RGB. The RGB signal is then passed through a video buffer and to the display. For still
image storage cases, the YUV 4:2:0 image passes through JPEG encoding and then transferred to a user selectable storage device(Flash, SD, MMC). For video cases, the
YUV 4:2:0 image is passed through MPEG4 or H.263 encoding. The video is then transferred to a user selectable storage device or sent as real time data transmission.
Motor
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Conf
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4-
50
Hall-Effect Switch
PCAP
Storage
FLASH
SD
MMC
LCD
208x320
TFT 65K color
Vcc
HELEN
I2C
GPIO
CAM_ROT_DETECT
SSCK, SSDA
VSYNCO, HSYNCO
Reset*
VAUX4_3V
SUSPEND
ICLK
VSync, HSync
PIXCLK
PIXVLD
Master I2C Slave
MSCK, MSDA
QCIF
Qualifier
Logic
DATA[7:0]
VODATA[7:0]
CAM_ICLK
XIN
Latch
Clock
Reset*
VAUX4_3V
Conexant
Backend
Processor
ASIC
IrDa_RX
IRDA_Shutdown
VODATA3
Suspend
Vcc
Reset*
Conexant
CMOS
Imager
U7605
U7602
U7600
YUV 4:2:2
to
YUV 4:2:0
Video
Buffer
YUV 4:2:0
to
RGB
Still Image
JPEG
Encoding
Video
MPEG4/H.263
Encoding
Real Time Data
Transmission
