STV0680B Datasheet, PDF (24/63 Pages) STMicroelectronics – DUAL-MODE DIGITAL CAMERA CHIPSET

STV0680B hardware interfaces
STV0680B + VV6444/6410/6500
into Suspend mode (in the case of VV6410/6411/6500). This has a significant improvement on
battery life.
4.6.3
Battery type
This is hardware dependant. The schematics referred to in Chapter 6 assume either three or four
1.5V cells.
4.7 Quartz crystal
Regardless of the sensor type or anti-flicker requirements, the sensor + STV0680B chipset
operates from a single 12MHz fundamental quartz crystal. For specification requirements, see
Table 13. STV0680B includes an on-chip low jitter PLL, for PLL characteristics, see Table 12.
4.8 Numeric LCD interface
STV0680B supports a 2-digit LCD panel only, for alpha-numeric display.
4.8.1
LCD types
STV0680B 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
The convention for segment numbering is as follows: ’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’s
The GPIO lines on STV0680B have pre-defined functions as follows, see Section 2.2 for user
interface functionality, and Chapter 6 for precise hardware implementation
4.9.1
MODE push button and SHUTTER push button: GPIO0 and GPIO1
Both 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: GPIO3
This allows for factory setting of the anti-flicker frequency, dependant on the final country of
destination. See also Section 2.6. The polarity of this selection is detailed in the reference design
(see Chapter 6).
4.9.3 LED indicator output: GPIO5
The LED output has an 8mA current sinking capability.
4.9.4 Other pins: GPIO2, 4, 6, 7
With STV0680B-001, these pins are un-used and should be tied to GND.
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