The STV0674 can be used to implement 3 different low-cost CMOS camera products as detailed
1.1 Webcam Mode
STV0674 allows a two-chip solution to provide a USB webcam, which can acquire and display
images on the host system at frame rates of up to 30fps VGA. The addition of an external
microphone allows simultaneous audio acquisition. Custom drivers require an additional low cost
EEPROM which allows USB parameters such as Vendor ID /Product ID to be customised.
1.2 Dual-Mode (Webcam plus Digital Still Camera)
While retaining all the features of the webcam, the addition of external storage memory allows the
functionality of a digital still camera. On-chip JPEG compression permits high-density picture
16Mbit to 128Mbit of SDRAM (8 or 16 bit) and/or 32Mbit to 1Gbit NAND flash memory are
supported by the device. Also supported are the popular Smart Media Cards (SMC) to extend non-
volatile storage capability. The wide range of memory support allows the camera builder to tailor the
system cost to suit their target market.
A continuous image acquisition mode allows untethered (no host connection) video clips to be
taken. As an example, with 15:1 compression ratio and 128Mbit memory over two minutes (QVGA
www.DataSheet4U.com@10fps) worth of video can be stored and up-loaded for display on the host.
Full Direct Show driver support for Windows 98SE, ME, Windows 2000, Win XP is available.
MacOS is currently in development.
1.3 Tri-Mode (Webcam plus Digital Still Camera plus Digital Movie/Audio
Again, retaining the features of the dual mode camera, the inclusion of audio record and playback
circuitry adds another dimension to the product. An in-system microphone allows audio to be
recorded and played back either via a speaker on the camera or via the host sound system. Audio
can either be recorded simultaneously with video (camcorder) or independently of image acquisition
(dictaphone). Audio data can also be downloaded from the host and played back on the camera
when events take place. This allows any sampled soundbites to be played back on cameras, as
opposed to the normal beeps from traditional cameras, which offers many possibilities for language
customisation or licensed “character” cameras.
As well as the memory and audio options already described, the GPIO and firmware emulation
make it possible to support other custom peripherals such as icon or area displays.
Other custom peripherals such as icon or area displays can be support via uncommitted general
purpose I/O under firmware control.
ST Microelectronics provides a software development kit (SDK) allowing OEMs to create custom
PC applications, and an OEM pack to modify drivers to their specific requirements.