VV6444C001 ,Low Cost Digital Camera (LCDC) ChipsetFEATURES• CIF (352 x 288) or VGA (640 x 480) resolution sensorSTMicroelectronics (ST), Imaging Divi ..
VV6500C001 ,DUAL-MODE DIGITAL CAMERA CHIPSETapplications to be written.continuous video capture is not possible.September 2001 Version 3.4 1/63 ..
VV6501C001 ,DUAL-MODE DIGITAL CAMERA CO-PROCESSORelectrical characteristics .....47Chapter 7 Optical Characteristics . . . .487.1 Optical char ..
VX-55-1A3 , Snap Action Switch
VX6953CBQ05I/1 ,5.1 megapixel EDOF camera moduleBlock diagram . . . . 173.2 Digital video block . . 183.2.1 Dark calibration algorithm ..
VY1222M47Y5UQ63V0 , Ceramic Disc Capacitors Safety Standard Approved Disc AC Capacitors
WSD411 , Surface Mount Schottky Barrier Diode
WSD411 , Surface Mount Schottky Barrier Diode
WSD520G , Surface Mount Schottky Barrier Diodes
WSD520S , Surface Mount Schottky Barrier Diodes
WSD551H , SMALL SIGNAL SCHOTTKY DIODES 500m AMPERES 30 VOLTS
WSD551H , SMALL SIGNAL SCHOTTKY DIODES 500m AMPERES 30 VOLTS
VV6444C001
Low Cost Digital Camera (LCDC) Chipset
PRELIMINARY
Low Cost Digital Camera (LCDC) Chipset
STV0680A + VV6444/6410/6500
DESCRIPTIONSTMicroelectronics (ST), Imaging Division (formerly VLSI
VISION Ltd.), has utilised its extensive experience in design-
ing imaging sensors for the digital still camera market to
develop chipsets for modular systems which will provide the
core of a highly cost-competitive new standard in consumer
digital stills cameras (DSC).
The Low Cost Digital Camera chipsets from ST, incorporat-
ing a CMOS imaging sensor and STV0680A co-processor
(formerly DCA1 ) enable camera manufacturers to offer an
end product which is genuinely price competitive with tradi-
tional ‘point and shoot’ film-based cameras.
The chipset provides the basis of an easy-to-use, user
friendly camera, which will be equally adaptable for use by
children and adults for stills photography or dual-mode use
(i.e. Digital stills while untethered, and videoconferencing
from the same camera).
Incorporating a wide range of features, the STV0680A
chipset offers exceptional performance at a very competitive
price point. ST’s aim is to enable manufacturers to offer fully
functional DSC products to the end consumer for between
$50 and $100. An evaluation kit (EVK) and reference design
manual are available, as well as standard TWAIN and Video
for Windows drivers. Alternatively, a software development
kit (SDK) allows access to ST colour processing algorithms
under licence, to develop OEM software.
The chipset incorporates ST’s high performance VV6444/
6410 CIF (352 x 288 pixel) or VV6500 VGA (640 x 480 pixel)
resolution CMOS sensors. The complete camera will have
20 picture storage capacity for CIF resolution or 80 for QCIF
resolution, when using 16MBit memory. When using 64MBit
memory, it will have 26 picture storage capacity for VGA res-
olution or 106 for QVGA resolution. A standby mode which
allows full picture retention at extremely low system power
consumption gives a battery life of up to several months.
An example upload and colour processing time for a CIF
image to the PC is 0.3 seconds when the USB interface is
used, and the chipset also offers a high frame rate tethered
USB video mode (dependant on PC and USB loading).
The chipset supports a 2x 7-segment display showing num-
ber of pictures remaining, a low battery indicator, and opera-
tion mode, as well as a buzzer indicating picture taken,
camera full, and self-timer countdown.
A CMOS solution gives manufacturers inherent benefits, pro-
viding a highly integrated compact solution which has a low
system cost, is straightforward to implement, and has low
power consumption, giving long battery life.
KEY FEA TURES CIF (352 x 288) or VGA (640 x 480) resolution sensor Using 64MBit memory, 80 picture storage capacity in
camera (CIF), 26 (VGA), or 320 (QCIF). Using 16MBit memory, 20 picture storage capacity, in
camera (CIF), or 80 (QCIF) USB/RS232 interface options Evaluation kit available Low power consumption (typically 75mA) for complete
camera and low system cost per pixel High speed picture upload with USB USB tethered video mode gives a QCIF resolution
videoconferencing camera with VfW support ‘Continuous’ mode for capturing image sequences (while
untethered) and downloading to AVI file format Memory refresh allows picture retention when camera is
in standby mode with very low current consumption TWAIN/Video for Windows driver support Numeric LCD panel supported Colour processing and pixel defect detection/correction
software available under license as SDK for development
of OEM software. The license to use the colour algorithm
(embedded in the PC driver software) is included in the
price of the chipset.
PRODUCT FORMATS For manufacturers wishing to design their own
cameras ST offers chipsets combining the colour CMOS
sensor with a companion processor.
An evaluation kit, including PC demo software, and a
comprehensive reference design manual are available,
including schematics and bills of materials.
modules are available to the basic specification outlined, but
geared to the customer’s individual requirements, subject to
commercial agreement with ST.
SOFTWAREDriver software is available to support both USB and RS232
interface, included in TWAIN and Video for Windows drivers
(VfW through USB only, WIN98). An AVI creator application
allows creation of video files from untethered ‘continuous’
mode images.
ST colour processing and defect detection/correction
software is supplied under licence agreement, as part of a
Software Development Kit (SDK). This runs on the host PC
under either Windows95TM or Windows98TM .
PRELIMINARY
Digital Camera Chipset; Customer Datasheet, Rev 3.0, March 2000 STV0680A + VV6444/6410/6500
This
version: ST VIBU internal use only
Table of Contents
1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71.1 Digital camera chipset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
1.2 Co-processor choices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
1.3 Sensor choices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4 Key system features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4.1 Image features (STV0680A-002). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4.2 Image features (STV0680-001) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4.3 User features on camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4.4 User features on PC software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4.5 Power management features and USB compliance . . . . . . . . . . . . . . . . . . . . . . . . . .9
1.4.6 General features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
2. Detailed features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102.1 Sensor type and image formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
2.1.1 VV6444 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
2.1.2 VV6410 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.1.3 VV6500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2 User interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2.1 Push buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2.2 LED indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2.3 Picture counter using 2 x 7 segment display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2.4 Piezo buzzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.3 Battery Level Detect and USB auto-switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
2.4 PC interface options and software support. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
2.4.1 USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
2.4.2 RS232 (not available on STV0680-001) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
2.5 Anti-flicker exposure and gain control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
3. Camera modes of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143.1 Standby mode (or USB suspend mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.1.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.1.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.1.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3.2 ‘Snapshot’ mode (in High or Low resolution) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.2.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.2.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.2.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.3 ‘Continuous Capture’ mode (in High or Low resolution) . . . . . . . . . . . . . . . . . . . . . . . .15
3.3.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.3.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.3.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.4 Self-timer Mode (in High or Low resolution) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.4.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.4.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.4.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5 ‘Clear camera’. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
3.5.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
PRELIMINARY
Digital Camera Chipset; Customer Datasheet, Rev 3.0, March 2000 STV0680A + VV6444/6410/6500
This
version: ST VIBU internal use only3.5.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.6 ‘Change resolution’. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.6.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.6.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.6.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.7 Tethered USB Video mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.7.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.7.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.7.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.8 Powering the camera off. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.8.1 Entering this mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.8.2 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
3.8.3 Exiting this mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
4. STV0680A hardware interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184.1 STV0680A pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4.2 Sensor interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4.3 Memory interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4.3.1 SDRAM Current consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4.3.2 SDRAM interface timing requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
4.3.3 SDRAM refresh Period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
4.3.4 SDRAM initialisation Period. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4.4 USB interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4.5 UART module for RS232 interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4.5.1 RS232 Physical interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4.5.2 UART Module Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4.6 Power management and battery type. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
4.6.1 Power switching to USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.6.2 Switched sensor supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.6.3 Battery type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.7 Quartz Crystal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.8 Numeric LCD interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.8.1 LCD types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.8.2 LCD interface pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.9 Switches and LED’s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.9.1 MODE push button and SHUTTER push button: GPIO0 and GPIO1 . . . . . . . . . . . .21
4.9.2 Input to select between 50 and 60Hz flicker frequency: GPIO3 . . . . . . . . . . . . . . . .21
4.9.3 LED indicator output: GPIO5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
4.9.4 Unused pins: GPIO2, 4, 6, 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
5. PC software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235.1 Driver support available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
5.2 Demonstration software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
5.3 OEM software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
5.4 Software Development Kit (SDK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
5.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
5.4.2 API Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
6. Customisation options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
7. Detailed chipset specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .267.1 Typical camera specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
PRELIMINARY
Digital Camera Chipset; Customer Datasheet, Rev 3.0, March 2000 STV0680A + VV6444/6410/6500
This
version: ST VIBU internal use only7.2 STV0680/STV0680A companion processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
7.3 VV6444 Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.4 VV6410 and VV6500 sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
7.5 Typical current consumption of complete camera . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
7.5.1 Using VV6444 (sensor operates at @ 5V DC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
7.5.2 Using VV6410/6500 (sensor operates at @ 3.3V DC) . . . . . . . . . . . . . . . . . . . . . . .33
8. STV0680A Pin descriptions and Package Information . . . . . . . . . . . . . . . . . . . . . . .348.1 STV0680A Pin Listing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
8.2 STV0680A pinout diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
8.3 STV0680A Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
9. Schematics and example parts list for complete camera design . . . . . . . . . . . . . .409.1 Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9.2 Example Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
10. VV6444 Sensor Pinout and Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . .4410.1 VV6444 Pin Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
10.2 VV6444 Pinout Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
10.3 VV6444 Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
11. VV6410 Pinout information and package dimensions . . . . . . . . . . . . . . . . . . . . . .5011.1 VV6410 pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
11.2 VV6410 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
11.3 VV6410 package Details (36pin CLCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
12. VV6500 Pinout and pin descriptions (48pin LCC package) . . . . . . . . . . . . . . . . . .5412.1 Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54
12.2 VV6500 pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
12.3 VV6500 package Details (48 pin LCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
13. Evaluation kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
14. Ordering details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59
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Revision notesThe following changes have been included since revision 2.00. Removed all schematics and only show example parts list, instead referring to respective reference designs (in Section 9.) Documentation now refers to STV0680A which supercedes STV0680 - see Section 1.2 for explanation. Clarified which STV0680/680A variants and which PC operating systems offer VfW support and RS232 support, offering VfW
support - see Table 3. Updated STV0680A pin descriptions (pinout not changed) in Section 8. Confirmed user interface functionality in Section 3. and added Table 6 to show modes of operation and button functions. Section 3.: Images captured in both ‘High’ and ‘Low’ resolution can be stored in camera memory at the same time. Therefore
there is no need for images stored in memory to be cleared before changing image resolution. Changed IR filter recommendation, see section Section 2.1.1. Added approximate shutter speeds, in Table 10. Adjusted sensor image array sizes in Section 7. to the correct sizes. Updated ordering information in Section 14. Updated current consumption information of STV0680, STV0680A, VV6444, and complete camera, see Section 7.2 and
Section 7.5. Added VfW framerates for STV0680A (Section 2.1). New order number STV0680A-002
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1.1 Digital camera chipsetThis document describes the features and functionality of a CMOS chipset, comprising an STMicroelectronics (ST) CIF or VGA
resolution sensor and an STV0680A companion processor (formerly known as DCA1: Digital Camera ASIC 1), as well as
outlining what peripheral components are required/supported in order to complete a camera using the chipset. Such a camera is
particularly suited to dual-mode digital stills or toy applications.
In stills mode, the camera stores raw image data in memory. The camera carries out no colour processing, ensuring its simplicity
and low cost. Subsequent download of raw data to a PC for processing is done through an RS232 (not STV0680-001) or USB
interface, through demo software, a TWAIN driver, or OEM custom application. The license to use the colour algorithm
(embedded in the PC driver software) is included in the price of the chipset.
A video option is provided, when tethered through USB, which can allow for Video for Windows applications, and ‘video clips’ can
be recorded while untethered by continuously capturing images while in ‘Continuous’ mode, then downloaded to the PC for
playback, using software to create an AVI file.
Precise design guidelines are available from ST as a reference design (see Section 9.) A PC software development kit (SDK) is
available from ST, to interface to the camera and provide the basis for developing a custom software application for stills and/or
video, which includes colour processing software.
Figure 1 : Typical camera system block diagram
1.2 Co-processor choicesThe following co-processor choices are available. The STV0680A supercedes STV0680, and uses different silicon and different
firmware compared to STV0680. Functionally it is exactly the same as STV0680 except that it supports a VfW driver. In addition,
a new firmware variant means that the STV0680A also supports VV6410 and VV6500 sensors, as well as 64Mbit memory size.
The firmware variant of STV0680 denoted by STV0680-001 does not support RS232 interface.:
Table 1 : Product choices
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1.3 Sensor choicesThe following sensors are supported:
1.4 Key system featuresThe key features of a typical camera based on the STV0680A chipset are as follows:
1.4.1 Image features (STV0680A-002) Support for 5V or 3.3V CIF resolution sensor (VV6444 or VV6410) - 352 x 288 pixels Support for 3.3V VGA resolution sensor (VV6500) - 640 x 480 pixels 80 picture storage capacity possible for CIF, with 64MB memory 26 picture storage capacity for VGA, with 64MBit memory A greater number of images can be stored when ‘Low’ resolution mode is enabled (e.g. 80 QCIF images with 16Mbit memory,
106 QVGA images with 64Mbit memory). See Table 4 and Table 5. Automatic anti-flicker exposure and gain control
1.4.2 Image features (STV0680-001) Supports 5V CIF resolution sensor (VV6444) - 352 x 288 pixels. 20 picture storage capacity possible for CIF with 16MB memory. 80 picture storage capacity possible for QCIF with 16MB memory. Automatic anti-flicker exposure and gain control
1.4.3 User features on camera Self-timer mode allows a picture to be captured after several seconds. Twin 7 segment LCD panel supported - showing number of pictures left, and modes. Picture counter helps the user to know how much memory is left. Un-tethered ‘Continuous’ mode allows capture of image sequences for storage in memory and subsequent download to PC. Piezo buzzer indicates a number of useful events to the user, e.g. whether enough light is present for picture capture, etc. Indicator LED.
1.4.4 User features on PC softwarePC software allows a number of features, including fast download of thumbnail images for picture selection, and automatic
detection and correction of sensor defects. Table 3 clarifies the driver compatibility available, including: TWAIN driver to suit all TWAIN compatible imaging applications Video for Windows driver for tethered video mode (through USB), available at all resolutions, with fastest framerates at QCIF
resolution
Table 2 : Sensor choices with STV0680/STV0680A
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Custom OEM software can be developed by using the SDK (for SDK availability, contact ST), to upload thumbnails/still images or
‘continuous’ images, e.g. for AVI file creation.
1.4.5 Power management features and USB compliance Picture retention with extremely low power operation, which appears to the user as if the camera is “switched off”. Auto power-off after 30sec with no user activity Operates from 6-9V battery, although system voltage is 5V or 3.3V, dependant on sensor. Low battery detection Dependant on hardware configuration, switch-over to USB power supply is supported, to allow the device to operate with low
batteries or without batteries, when connected to USB. Full USB compliance requirements are listed in the USB specification, however, in a camera designed using this chipset, the
following must at least be included: (a) an SDRAM with sufficiently low self-refresh current, (b) USB inrush protection circuitry,
and (c) (in the case of VV6444 only) a switched 5V sensor supply is used, to maintain sufficient supply voltage to the 5V
sensor. See Section 9. for further details.
1.4.6 General features High speed picture download over USB ST Colour processing algorithms available under license (as part of drivers/SDK) USB or RS232 serial interface options, and VfW / TWAIN driver support. Customisation of STV0680A is possible to vary the features described in this document, subject to commercial agreement
with ST, see Section 6.
Table 3 : Driver choices
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version: ST VIBU internal use only Detailed features
2.1 Sensor type and image formatsThe sensor type is auto-detected by STV0680A, which ensures that the correct sensor timing is enabled, and the correct image
resolutions are enabled, as shown in Table 4.
For stills photography, ‘High’ or ‘Low’ resolution mode can be selected, to give CIF or QCIF pictures from a CIF sensor, and VGA
or QVGA from a VGA sensor (see Table 4 and Section 3.7). Reduced resolution allows for storage of more images. Images
captured in both ‘High’ and ‘Low’ resolution can be stored in camera memory at the same time. Therefore there is no need for
images stored in memory to be cleared before changing image resolution.
Where USB is connected, the host PC software (through a Video for Windows driver) can activate tethered video mode,
regardless of the user inputs to the camera buttons. In this case, the image resolution is controlled by the PC driver..
2.1.1 VV6444VV6444 is a CIF resolution, 5V CMOS imaging sensor. A brief specification is shown in Section 7. VV6444 has the same
functionality and array size as the un-microlensed VV6404 sensor, but has a microlensed array and different colour
characteristics. Although the VV64444 and VV6404 are electrically identical, the STV0680 and STV0680A use the correct
Table 4 : Image modes supported (STV0680A-002)*Notes: VfW framerate is dependant on PC performance and USB bus loading Not all image sizes are supported by all STV0680/680A variants - see T able 2 for clarification. A CIF camera with STV0680A-002 and 64Mbit SDRAM can store up to 320 images by using QCIF mode. Where >99 images
are still available, the LCD display will remain at 99. Where (no. of images available) <99, the LCD display will show the
number of images available, as is the case with all other modes.
Table 5 : Image modes supported (STV0680-001)
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onlsettings for the VV6444 colour set. This means that a VV6404 should not be used with STV0680/680A.
For IR filter design, the best choice filter follows the GS0034 dielectric stack filter specification, which is available from ST. An
alternative, although not optimal filter, would be Schott S8612 doped glass, also sold as CM500.
2.1.2 VV6410VV6410 is a CIF resolution, 3.3V CMOS imaging sensor. A brief specification is shown in Section 7.
A dual design to support VV6444 and VV6410 is not possible, since VV6410 is a 3v3 sensor. A dual footprint for VV6410 and
VV6500 is not possible since the package types differ, however, the same support circuit is used. See Section 9.
2.1.3 VV6500VV6500 is a VGA resolution, 3.3V CMOS imaging sensor. A brief specification is shown in Section 7.
A dual design to support VV6444 and VV6500 is not possible, since VV6500 is a 3v3 sensor. A dual footprint for VV6410 and
VV6500 is not possible since the package types differ, however, the same support circuit is used. See Section 9.
2.2 User interfaceThe user interface supported by STV0680A comprises of user controls, audible signals and visual displays.
2.2.1 Push buttonsThe following are typical of the type of functions which are supported by the chipset. These functions are achievable with no more
than 2 push buttons. Mode button (Wake-up/Switch between modes): This button allows the user (1.1) to wake the camera up from standby mode
when the camera is to be used for taking pictures, or (1.2) to switch between modes of operation shown in Section 3.. Shutter button (Shutter/confirm action): This button allows the user to take a picture or confirm an action, as shown in Sec-
tion 3.
The modes of operation are described in Section 3.
2.2.2 LED indicatorAn LED display camera status, i.e. to show that the camera is in ‘Snapshot’ mode.
2.2.3 Picture counter using 2 x 7 segment displaySTV0680A stores a picture counter value, which shows how many images can still be captured. STV0680A supports a 2x7
segment LCD panel. In ‘Snapshot’ mode and continuous capture mode, this LCD panel displays the number of pictures still
available, which is useful to identify when the user is approaching the maximum number of images which can be stored (see
Table 4 and Table 5). It is possible to clear the images stored in memory, in order to continue taking pictures, as shown in Table
6. In other modes, this LCD panel shows displays a 2-character code as shown in Table 6, which helps the user to navigate
around the modes.
Note: A CIF camera with STV0680A-002 and 64Mbit SDRAM can store up to 320 images by using QCIF mode. Where >99
images are still available, the LCD display will remain at 99. Where (no. of images available) <99, the LCD display will show the
number of images available, as is the case with all other modes.
For suitable numeric LCD panel types, see Section 4.8.
2.2.4 Piezo buzzer An on-chip Pulse Width Modulator (PWM) on STV0680A is used to generate buzzer sounds to signal certain events. The
following are typical of the type of events which are indicated by the buzzer, and each has its own distinctive sound: Camera has been ‘Woken up’ from standby mode (either by the user pressing a button, by re-connecting the power source,
or by connecting a USB/RS232 connection).
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version: ST VIBU internal use only Camera has been ‘gone to sleep’ i.e. moved into standby mode. Pictures are retained in memory. Picture has been successfully taken after the user presses the capture button. Picture has NOT been taken after the user presses the capture button. This indicates to the user that there is insufficient
light, or that the exposure control was not ready due to a rapid change of lighting in the scene. Picture has NOT been taken after the user presses the capture button, due to picture counter having reached the maximum
number of images. The user has the chance to zero the counter if desired. End of continuous capture in un-tethered ‘Continuous’ mode, due to memory full. Self-timer activated and counting down.
2.3 Battery Level Detect and USB auto-switchAn on-chip battery level detector on STV0680A detects when the battery voltage falls below a threshold. This threshold is
determined by the designer, dependant on the perception of what remains as ‘acceptable’ image quality as the battery voltage
falls. The chosen threshold level is determined by a resistor value, as shown in Section 9. Where no USB has been detected, the
LCD display flashes, which indicates that the battery is low. Where a USB connection has been detected, the camera sources
power from USB, if certain additional hardware is fitted.
order to enable the camera to switch to supply from USB and hence report back to the PC while connected to the USB bus
without a battery.
2.4 PC interface options and software supportEither USB Interface (full speed 12Mbit/sec max.) or RS232 interface (115.2Kbaud) is supported by the chipset, with driver
software available from ST for both. The interface type is auto-detected by the chipset. PC software can be one of the following
(exact compatibility is clarified in Table 3): Simple image upload demonstration software supplied by ST , allowing uploading of stills or ‘continuous’ images. This soft-
ware should not be supplied as an end-user product. TWAIN driver to suit all TWAIN compatible imaging applications Video for Windows driver for tethered video mode (USB only) Custom end-user software developed by OEM using SDK (for SDK availability, contact ST). The SDK is supplied by ST as a
32-bit DLL format, running on Windows 98, and accessed through a documented software interface. This provides the basis
for developing a custom software application for uploading stills and/or video. See Section 5. for further details.
2.4.1 USBComplete images (displayed as either thumbnails or in full resolution), or the entire SDRAM contents (e.g. for uploading
continuously captured image sequences, recorded using ‘Continuous Capture’ mode) can be downloaded through USB, and
USB connection also allows for tethered video mode to be activated by the USB driver.
Thumbnail image download is extremely fast for the entire memory contents in the camera. Once a picture is selected for
download, full image download takes approximately 0.15 seconds per image for a CIF image (0.6 seconds for a VGA image),
plus post processing time per image.
For USB interface details, see Section 4.4.
2.4.2 RS232 (not available on STV0680-001)Thumbnails of images, complete stored images, or the entire SDRAM contents can be downloaded through RS232, but tethered
video is not supported.
Once a picture is selected for download, full image download takes approximately 10 seconds per image for a CIF image (around
30 seconds for a VGA image), plus post processing time per image (of the order of 1 second approximately).
For RS232 interface details, see Section 4.5.
2.5 Anti-flicker exposure and gain controlThe chipset operates automatic exposure and gain control for either 50Hz or 60Hz mains-driven indoor lighting, using the same
12MHz crystal. This improves picture quality by selecting a set of exposure values which minimise ‘flicker’ effects. Detection of
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onlthe mains frequency is dependant on the status of the GPIO3 pin, which can be achieved by population of a PCB link at a late
stage in production, once the country of destination is known, without the need to change the crystal frequency.
The auto exposure and gain algorithm is always enabled during ’Snapshot’/self-timer/continuous mode. When the shutter button
is pressed in ‘Snapshot’ mode, the chipset captures an image if the exposure and gain value has reached a suitable value for the
current scene. If the light detected has suddenly changed, the camera may emit an audible tone to indicate that more time is
required to reach the correct exposure target. In ‘Snapshot’ mode the chipset only captures the image data if sufficient light is
present in the image. In continuous capture mode, the chipset captures images regardless of whether enough light is present.
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version: ST VIBU internal use only Camera modes of operationThe above modes are interrupted by the detection of a USB or RS232 connection. This is to allow for the possibility that the PC
driver takes control of the chipset (e.g. when starting a VfW application through USB).
3.1 Standby mode (or USB suspend mode)
3.1.1 Entering this modeThe camera enters standby mode automatically after 30 seconds of inactivity if not tethered to USB, or when USB suspend mode
is activated by the PC driver.
3.1.2 DescriptionThis allows image data to be stored in memory with extremely low power consumption, which appears to the user as if the
camera is switched ‘off’, since there is no LCD display or LED lit. In VV6444-based designs, STV0680A powers off the sensor
completely, in VV6410/6500 based designs, the sensor is placed in suspend mode, and the camera enters a mode where only
SDRAM refresh is carried out. The shutter button is inactive in standby mode.
3.1.3 Exiting this modeWake-up from standby mode is achieved by any of the following means: Pressing the ‘mode’ button (only if no USB detected)
Table 6 : Camera modescamera has no images stored. This is because in STV0680-001, mixed resolutions (i.e. ‘High’ and ‘Low’) cannot be stored at the
same time. In STV0680A-002, mixed resolutions can be stored at the same time.
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3.2 ‘Snapshot’ mode (in High or Low resolution)
3.2.1 Entering this modeThis is the default mode on wake-up when not tethered to the PC, i.e. pressing the Mode button while in standby mode, or
powering up the camera. On entering this mode, the current resolution (i.e. ‘Hr’ or ‘Lr’) is displayed briefly, and there is a brief
pause (approx. 1second) during which pictures cannot be taken. This is to allow the Auto-exposure and Gain control to settle.
The LCD then displays the number of pictures still available.
3.2.2 DescriptionUsing the shutter button, ‘Snapshot’ mode allows single pictures to be grabbed using the capture button. The LCD displays the
number of pictures still available. Auto-exposure and gain are continuously enabled. The camera grabs an image when the
capture button is pressed, if sufficient light is available, the exposure and gain algorithm is settled, and picture counter has not
reached its maximum. Image data is stored in memory and picture counter is decremented.
3.2.3 Exiting this modeAfter 30 seconds of non-activity, while not tethered to the PC, the camera goes into Standby mode.
3.3 ‘Continuous Capture’ mode (in High or Low resolution)
3.3.1 Entering this modeEnabled using the mode button (from ‘Snapshot’ mode, press once).
3.3.2 DescriptionThe LCD displays “Ct”. Auto-exposure and gain are continuously enabled. While the shutter button is pressed, the user can
activate continuous capture at approx. 12.5 frames per second, to allow recording of a ‘video’ sequence, whether or not the
camera is tethered to the PC, and regardless of whether enough light is available. The picture counter is decremented once per
frame. The continuous image data is stored in memory and can then be downloaded to the PC. Once the memory is full, the user
is alerted by an audible tone. It is possible to store a mixture of still images and ‘Continuous’ images in memory.
3.3.3 Exiting this modeAfter 5 seconds of non-activity, or after releasing the shutter button, the camera returns to standby mode.
3.4 Self-timer Mode (in High or Low resolution)
3.4.1 Entering this modeEnabled using the mode button (from ‘Snapshot’ mode, press twice).
3.4.2 DescriptionThe LCD displays “St”. Auto-exposure and gain are continuously enabled. When the shutter button is pressed, the camera counts
down 10 seconds, then grabs an image, if sufficient light available and exposure and gain algorithm settled, and picture counter
has not reached its maximum. Image data is stored in memory and picture counter is decremented.
3.4.3 Exiting this modeAfter 5 seconds of non-activity, or after the timer has counted down 10 seconds, the camera returns to standby mode.
3.5 ‘Clear camera’
3.5.1 Entering this modeEnabled using the mode button (from ‘Snapshot’ mode, press three times).
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3.5.2 DescriptionThe LCD displays “CL”. Pressing shutter button twice will clear all the images in the camera.
3.5.3 Exiting this modeAfter 5 seconds of non-activity, or after the camera has been cleared, the camera returns to standby mode.
3.6 ‘Change resolution’
3.6.1 Entering this modeThis is enabled using the mode button (from ‘Snapshot’ mode, press four times).
STV0680-001, mixed resolutions (i.e. ‘High’ and ‘Low’) cannot be stored at the same time.
3.6.2 DescriptionThe LCD displays the target resolution to which the camera can be changed, i.e. if in High resolution “Lr” (Low resolution) is
displayed, if in Low resolution, “Hr” (High resolution) is displayed. ‘High’ resolution stores the full image resolution from the sensor
array, while ‘Low’ subsamples the sensor array, to store 4x the number of images (e.g. 80 in QCIF mode, compared to 20 in CIF
mode).
Dependant on the type of sensor used, different resolutions are obtained, see Table 4 or Table 5. By pressing the shutter button,
user changes the resolution.
3.6.3 Exiting this modeAfter 5 seconds of non-activity, or after the resolution has been changed, the camera returns to standby mode.
3.7 Tethered USB Video mode
3.7.1 Entering this modeThis is activated by the PC Video for Windows driver while the camera is tethered, dependant on whether VfW is supported (see
Table 3).
3.7.2 DescriptionThe camera is controlled by the PC driver.
3.7.3 Exiting this modeThis is controlled by the PC drivers.
3.8 Powering the camera off
3.8.1 Entering this modeThis is not truly a mode of operation, but a description of what happens if: The battery power and USB connection are removed from the camera The battery power is removed, and the PC to which the camera is tethered, is switched off. The battery voltage falls extremely low. Ways of avoiding this situation are discussed in the reference design, see Section 9.
Section 9.
3.8.2 DescriptionIn this situation, all image data is lost.
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3.8.3 Exiting this modeWhen the camera is powered on again, either when the battery is re-fitted, or the USB is re-connected, or the PC is re-started, the
camera will power up into standby mode, High resolution, with all images available.
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4.1 STV0680A pinoutThe STV0680A pinout has been carefully developed to minimise the physical size of the support printed circuit board by
facilitating placement of and electrical routing to peripheral support components such as the SDRAM. The complete pinout and
listing is shown in Section 8.
4.2 Sensor interfaceSTV0680A uses a standard ST digital interface from the sensor, and the sensor clock input is provided by an output from
STV0680A. Designing a camera using this chipset should design as close as possible to the reference design (Section 9.), in
which case the chipset can be regarded as a functional ‘black box’, and no further details regarding the STV0680A-sensor
interface are required.
4.3 Memory interfaceSTV0680A is designed to interface to an external 16Mbit or 64Mbit SDRAM (see Table 4 and Table 5). The SDRAM device must
have a 16 bit wide data bus and operate from a 3.3V supply. Two sizes of SDRAM memory are supported by STV0680A, 16MBits
(1M x 16 bits wide) or 64MBits (4M x 16 bits wide), the memory size is auto-detected by STV0680A. STV0680A clocks the
SDRAM at 6MHz, typically this is well below the figures offered by most manufacturers’ devices. Devices which are PC66 and/or
PC100 compliant are preferred. For interface wiring, see Section 9.
4.3.1 SDRAM Current consumptionFor maximum system battery life while no pictures are being taken, and to assist in meeting requirements for USB compliance, an
SDRAM should be chosen with the lowest possible self refresh current specification. For suggested SDRAM part numbers, see
Section 9.
4.3.2 SDRAM interface timing requirementsThe following timing diagrams should be referred to when selecting SDRAM other than those recommended in Section 9.
DCLK
Command
DQM
A0-9,BA
A10DQ
tCK
tRCD
tRC
CKE
DQ sample DQ sample DQ sample DQ sample
tCMS tCMH
tAS tAH tH
tCMS tCMH
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Figure 2 : SDRAM Read Timing (16Mbit device, burst read)
Figure 3 : SDRAM Write Timing (16Mbit device, burst write)
Table 7 : Timing parameters for SDRAM read/write
4.3.3 SDRAM refresh PeriodThe SDRAM refresh period from STV0680A is guaranteed to be no greater than 15.6μS during ‘Snapshot’/self-timer/continuous/
tethered video modes of operation (i.e. not standby mode). In standby mode, the SDRAM is set to self-refresh, therefore no
DCLK
Command
DQM
A0-9,BA
A10DQ
tCK
tRCD tRC
CKE
tCMS tCMH
tAS tAH tH
tCMS tCMH
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4.3.4 SDRAM initialisation PeriodThe SDRAM initialisation period is currently set to 981μS in STV0680A.
4.4 USB interfaceSTV0680A includes a USB Version 1.1 compliant Universal Serial Bus Interface, including a transceiver. This allows direct
connection from STV0680A to a USB connector with minimal additional hardware (i.e. a small number of passive discretes) - see
Section 9.
The USB interface interfaces the STV0680A to the USB at full speed 12MHz data rate. Some of the features are: Compliant with USB protocol revision 1.1. USB protocol handling. USB device state handling. Clock and data recovery from USB. Bit stripping and bit stuffing functions. CRC5 checking, CRC16 generation and checking. Serial to parallel conversion. Single bulk end point.
USB drivers are supplied by ST. For USB timing information, please refer to the USB specification V1.1.
4.5 UART module for RS232 interfaceThe UART module on STV0680A provides a 115200 baud full duplex interface to an external Host.
4.5.1 RS232 Physical interfaceSTV0680A does not support direct connection to a serial link. Physical line driver circuitry is required, e.g. using a standard
RS232 transceiver chip, or by using a small number of low cost discretes (as shown in Section 9.). The schematics shown
assume a 3 core cable with a length of no greater than 2m. Unscreened cable can be used, a suitable low cost connector is a
3.5mm audio jack plugs/sockets.
4.5.2 UART Module OverviewThe UART module in STV0680A receives serial data through the RXD pin. Data reception is initiated by a 1-to-0 transition on
RXD, and the received data is sampled every 8.66μS.
If the RXD input is not 0 when the incoming data is first sampled, the UART module goes back to look for another 1-to-0
transition. This is to provide rejection of false start bits. If the start bit proves valid, reception of the rest of the frame will proceed.
When a transmission is activated by STV0680A, the contents of an internal transmit shift register are shifted onto the TXD pin,
every 8.66μS.
The UART operates at 12MHz, which is not an integer multiple of 115200, so the actual baud rate is 115232 +/- 0.3%, which is
well within the requirements of a typical 16x oversampling UART, which can tolerate a 3.75% error in baud rate.
4.6 Power management and battery typeSTV0680A and the SDRAM require a 3.3V supply. Where a VV6410 or VV6500 (3.3v) sensor is used, a single voltage regulator
can be used to regulate the supply for all three components from the battery, or the sensor on-board VReg can be used. Where a
VV6444 is used, the sensor requires a 5V supply, hence a DC-DC converter is recommended to provide enough voltage when
the camera is powered from the USB bus. These are explained more fully in the reference design.
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4.6.1 Power switching to USBIncluded in the USB compliance requirements, is the ability of the camera to report to the PC when connected to the USB bus,
whether or not there is a fresh battery in the camera. This means that power sourcing from USB is required, which also saves on battery life while the camera is used in USB tethered video mode. In order to allow switching from battery to USB power, some
additional hardware is required (see also Section 9.): The USBDETECT input to STV0680A is used to detect that a USB power supply is connected If the USB is detected, additional hardware is used to switch off the battery An inrush protection circuit can protect the USB bus from current draw in the case of a low battery/battery not fitted. This may
be necessary to comply with the USB specification. For precise USB compliance requirements, please consult the USB specification version 1.1
4.6.2 Switched sensor supplyDependant on the hardware implementation, the SENSPWR output from STV0680A can be used to power off completely the
sensor during Standby mode (in the case of VV6444) or put the sensor into Suspend mode (in the case of VV6410/6500). This
has a significant improvement on battery life.
4.6.3 Battery typeThis is hardware dependant. The schematics referred to in Section 9. assume either three or four 1.5V cells.
4.7 Quartz CrystalRegardless of the sensor type or anti-flicker requirements, the sensor + STV0680A chipset operates from a single 12MHz
fundamental quartz crystal. For specification requirements, see Table 15. STV0680A includes an on-chip low jitter PLL, for PLL
characteristics, see Table 14.
4.8 Numeric LCD interfaceSTV0680A supports a 2-digit LCD panel only, for alpha-numeric display.
4.8.1 LCD typesSTV0680A connects to a non multiplexed, direct drive LCD with 2 x 7 segments. Many LCD types are compatible with this
interface. The LCD refresh frequency is 34.7Hz.
4.8.2 LCD interface pinout'0' connects to segment 'a', '1' connects to segment 'b', and so on, where a to g are standard for all 7-segment displays, as well as
an LCD common output, giving fifteen signals in total.
4.9 Switches and LED’sThe GPIO lines on STV0680A have pre-defined functions as follows, see Section 2.2 for user interface functionality, and Section
9. for precise hardware implementation.
4.9.1 MODE push button and SHUTTER push button: GPIO0 and GPIO1Both push button inputs have internal de-bounce circuits, reducing the amount of hardware required externally. It is
recommended that labelling is used on the camera casing to help the user understand the functioning of the 2-button interface.
4.9.2 Input to select between 50 and 60Hz flicker frequency: GPIO3This allows for factory setting of the anti-flicker frequency, dependant on the final country of destination. See also Section 2.5.
The polarity of this selection is detailed in the reference design (see Section 9.).
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4.9.3 LED indicator output: GPIO5The LED output has an 8mA current sinking capability.
4.9.4 Unused pins: GPIO2, 4, 6, 7These should be tied to GND.
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5.1 Driver support available
5.2 Demonstration softwareThe following is supplied with evaluation kits/demonstration units (This software is mainly for demonstration purposes and should
NOT be supplied as an end-user product.):
5.3 OEM softwareOEM’s have the following options for productisation of a camera based on the chipset:
software.
bundled with standard video for windows software.
5.4 Software Development Kit (SDK)
5.4.1 GeneralA software development kit is supplied by ST under license agreement, which allows the OEM to develop a custom application
which can perform picture download, thumbnail display, and colour processing. This supports Windows95TM (Serial interface
only) or Windows98/Win2KTM (Serial or USB), and includes features such as: Very fast download (through USB) and colour display of image thumbnails for picture selection Download of full image once selected by user software Colour processing of full image, using the ST colour process Automatic detection and correction of sensor defects
The SDK is supplied by ST as a 32-bit DLL format, running on Windows 98/Win2KTM , and accessed through a documented
software interface. This provides the basis for developing a custom software application for stills and/or video.
The ST SDK for the chipset comprises the following: Interface library containing all Application Programmer’s Interface (API) functions. Provided as C library and header files. All driver files necessary for chosen communications link (supplied as DLL and SYS files). Documentation of all API functions including example code fragments.
All software is built as 32-bit modules for Windows 98/Win2K. The serial communications link is also supported for Windows 95.
A development environment of Microsoft Visual C++ v5 or higher is assumed.
Table 8 : Driver choices
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5.4.2 API OverviewAll OEM application software communicates with the camera by means of the API as illustrated in Figure 4.
Figure 4 : Software interfaceThe user application, API and drivers all run on the host PC. The drivers communicate with the camera by the chosen
communications link (either serial or USB). The core API functions allow for: The camera to be opened and closed as a device under the operating system Query of camera information and configuration (e.g., the number of pictures taken, current mode setting) Uploading of images and thumbnail images Control of camera functions (e.g., taking a picture or resetting the image counter).
Both single-threaded and multi-threaded programming models are supported and the camera may be accessed using either
synchronous (i.e., blocking) or asynchronous (i.e., non-blocking or overlapped) communications. Where asynchronous
communications are used, the application developer is responsible for coordinating tasks and access to the camera.
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subject to commercial agreement for high volume applications, the configuration of STV0680A could be modified by ST to allow a
new chipset to be produced.
Please contact ST for details.
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7. Detailed chipset specifications
7.1 Typical camera specificationsThe following data assumes that the camera has been built according to reference design shown in Section 9.
7.2 STV0680/STV0680A companion processor
Table 9 : Typical camera specifications Dual USB or battery power supply is only possible when the required power switching hardware is included, as shown in
Section 9. Figures are approximate and depend on actual components sourced.
Table 10 : Approximate shutter speeds
Table 11 : STV0680/STV680A Specifications
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Table 12 : STV0680/STV0680A Absolute Maximum Ratings
Table 13 : STV0680/STV0680A DC Characteristics VDI = |(D+) - (D-)| VCM includes VDI range. TFRFM =( TFR / TFF ). ZDRV includes an external resistor of 20 Ohms serial to this transceiver.
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Table 14 : STV0680/STV0680A PLL Characteristics
Table 15 : STV0680/STV0680A Crystal Tolerance
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7.3 VV6444 Sensor
7.4 VV6410 and VV6500 sensors
Table 16 : VV6444 Specifications* Notes: 48dB refers to VV6404. With the addition of microlenses on VV6444, an increase in sensitivity can be expected. Where the sensor is completely powered off by a FET or switcher (external hardware) during the Standby/PC Suspend
Mode. Where the FET/switcher is not implemented, and the sensor is powered throughout Standby/PC Suspend Mode, however
the sensor clock is disabled.
Table 17 : VV6444 DC Characteristics
Table 18 : VV6410 Specifications
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version: ST VIBU internal use only Assuming appropriate external hardware recommendations are implemented (see Section 9.), the sensor SUSPEND pin is
asserted during Standby Mode/PC Suspend Mode. Hence the sensor is placed in Sensor Suspend mode by means of (a) a
Serial interface message and (b) the SUSPEND pin being asserted. Where the external hardware does not permit the sensor SUSPEND pin to be asserted during Standby Mode/PC Suspend
Mode, the sensor is placed in Sensor Suspend mode by means of a Serial interface message only. This increases current
consumption due to a pull-up on the SUSPEND pin. Assuming appropriate external hardware recommendations are implemented (see Section 9.), the sensor SUSPEND pin is
Table 19 : VV6500 Specifications
Table 18 : VV6410 Specifications
