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STV0674

Overview

1

Overview

The STV0674 can be used to implement 3 different low-cost CMOS camera products as detailed

here below.

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

storage.

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

@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

Recorder)

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.