C328-7640
JPEG Compression
VGA Camera Module
General Description
The C328 JPEG compression module performs as a video camera or a JPEG compressed still
camera and can be attached to a wireless or PDA host. Users can send out a snapshot command
from the host in order to capture a full resolution single-frame still picture. The picture is then
compressed by the JPEG engine and transferred to the host.
Block Diagram
VCC
OV7640
VGA
Image
Sensor
GND
TxD
RxD
OV528
Compression
Engine
EEPROM
(program)
Features
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Low-cost, & low-powered solution for high resolution image capture
Built-in down-sampling, clamping and windowing circuits for VGA/CIF/SIF/QCIF/160x128/80x64
image resolutions
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RS-232: 115.2K bps for transferring JPEG still pictures or 160x128 preview @8bpp with 0.75~6
fps
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JPEG CODEC for different resolutions
Built-in color conversion circuits for 4 gray/16 gray/256 gray/12-bit RGB/16-bit RGB preview
images
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Auto detect baud rate and make connection to the host
System Configuration
Camera Sensors
The C328 uses OmniVision OV7640/8 VGA CameraChips with an 8-bit YCbCr interface.
OV528 Serial Bridge
The OV528 Serial Bridge is a controller chip that can transfer image data from CameraChips to
external device. The OV528 takes 8-bit YCbCr 422 progressive video data from an OV7640
CameraChip. The camera interface synchronizes with input video data and performs down-sampling,
clamping and windowing functions with desired resolution, as well as color conversion that is
requested by the user through serial bus host commands.
The JPEG CODEC with variable quality settings can achieve higher compression ratio & better
image quality for various image resolutions.
Program Memory
A serial type program memory is built-in for C328, which provides user-friendly commands to
interface external control units.
Pin Description
VCC
Pin
Description
TxD
RxD
GND
VCC
TxD
RxD
GND
Power 3.3VDC
Data Transmit (3.3V)
Data Receive (3.3V)
Power Ground
