STV-5410-R01 STMICROELECTRONICS [STMicroelectronics], STV-5410-R01 Datasheet - Page 83

• 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
9.6.3
When a location is to be read, but the value of the stored index is not known, a write message with no data byte must be written
first, specifying the index. The read message then completes the message sequence. To avoid relinquishing the serial to bus to
another master a repeated start condition is asserted between the write and read messages, i.e. no stop condition is asserted. In
this example, the gain value (index = 36
As mentioned in the previous example, the read message is terminated with a negative acknowledge (A) from the master.
9.6.4
It may be desirable to write a succession of data to a common location. This is useful when the status of a bit (e.g. auto-load)
must be toggled.
The message sequence indexes sf_setup register 108. If bit 0 is toggled high, low this will initiate a fresh auto-load. This is
achieved by writing two consecutive data bytes to the sensor. There is no requirement to re-send the register index before each
data byte.
9.6.5
When an exposure related value ( fineH, fineL, coarseH, coarse L , gain or clk_div ) is written, it takes effect on the output at the
beginning of the next video frame, (remember that the application of the gain value is a frame later than the other exposure
parameters). To signal the consumption of the written value, a flag is set when any of the exposure or gain registers are written
and is reset at the start of the next frame. This flag appears in status0 register and may be monitored by the bus master. To
speed up reading from this location, the sensor will repeatedly transmit the current value of the register, as long as the master
acknowledges each byte read.
In the below example, a fineH exposure value of 0 is written, the status register is addressed (no data byte) and then constantly
read until the master terminates the read message.
No data write followed by same location read.
Same location multiple data write.
Same location multiple data read
S
S
32
Write to pin_mapping
10
33
10
No data write
A
Figure 40 : No data write followed by same location read.
A
0
0
Figure 41 : Same location multiple data write.
21
10
36
) is read as 15
10
Commercial in confidence
10
cd5410-6410f-3-0.fm
A
A
Sr
10
4
10
:
33
10
Toggle control bit
A
Read index and data
A
0
0
10
36
A
10
4
A
10
15
P
10
VV5410 & VV6410
A
P
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