STV-5410-R01 STMICROELECTRONICS [STMicroelectronics], STV-5410-R01 Datasheet - Page 23

• Manufacturer Part Number: STV-5410-R01
• Description: Mono and Colour Digital Video CMOS Image Sensors
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

CMOS Sensor; Customer Datasheet, Rev 3.0, 28 September 2000
6.4
Although the user can write a new exposure, gain or clock division parameter at any point within the field the sensor will only
consume these new external values at a certain point. The exceptions to this behaviour are when the user has selected
immediate update of gain and clock division. If the user has selected the former then the new gain or clock division value will be
applied as soon as the serial interface message has completed. The fine and coarse exposure values are always written in a
“timed” manner. There are a number of “update pending” flags available to the user (see Status0 reg[2] for details) that allows the
user to detect when the sensor has consumed one of the timed parameters. In the next section of this document we will detail all
the timed parameters and describe when they are updated.
It is important to realise that there is a 1 frame latency between a new exposure value being applied to the sensor array and the
results of this new exposure value being read-out. The same latency does not exist for the gain value. To ensure that the effect of
the new exposure and gain values are coincident the sensor delays the application of the new gain value by approximately one
frame relative to the application of the new exposure value.
If the user is using the autoincrement option in the serial interface when writing a new series of exposure/gain and clock division
parameters then it is important to ensure that the sensor receives the complete message bunch before updating any of the
parameters. It is also important that the timed parameters are updated in the correct order, we will discuss this fully in the next
section. If an autoincrement message sequence is in progress but we have reached the point in the field timing where the gain
value would normally be updated, we actually inhibit the update. We inhibit the update to ensure that the gain change is not
passed to the sensor while a change in the exposure is still pending.
Updating Exposure, Gain and Clock Division Settings
Video mode
PAL/NTSC
QCIF
CIF
Table 8 : System Clock Divisor Options
Commercial in confidence
cd5410-6410f-3-0.fm
Register[37], bits[7:4]
4’b0001
4’b0011
4’b0000
Effective system clock divisor
Divide CLKI/CLKIP by 4
Divide CLKI/CLKIP by 8
Divide CLKI/CLKIP by 2
VV5410 & VV6410
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