AD9992_07 AD [Analog Devices], AD9992_07 Datasheet - Page 50

• Manufacturer Part Number: AD9992_07
• Description: 12-Bit CCD Signal Processor with Precision Timing Generator
• Manufacturer: AD [Analog Devices]

AD9992
FIELD COUNTERS
The AD9992 contains three field counters (primary, secondary,
and mode). When these counters are active, they increment
with each VD cycle. The mode counter is the field counter used
with the mode register to control the vertical timing signals (see
the MODE Registers section. The primary and secondary
counters are more flexible and are generally used for shuttering
signal applications. Both the primary and secondary counters
have several modes of operation that are dictated by Address
0x70, including
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Table 22. Primary/Secondary Field Counter Registers (Address 0x70, Address 0x71, and Address 0x72)
Register
PRIMARY_ACTION
SECOND_ACTION
PRIMARY_MAX
SECOND_MAX
VDHD_MASK
PRIMARY_DELAY
PRIMARY_SKIP
SECOND_DELAY
SECOND_SKIP
Normal (single count)
RapidShot (repeating count)
ShotDelay (delayed count)
3b
3b
13b
12b
1b
Length
3b
13b
1b
13b
Description
0: Idle, no counter action. GPO signals can still be controlled using polarity or GP_PROTOCOL = 1.
1: Activate counter. Single cycle of counter from 1 to counter maximum value, and then returns to idle state.
2: RapidShot. After reaching maximum counter value, counter wraps and repeats until reset.
3: ShotTimer. Active single cycle of counter after added delay of N fields (use the corresponding DELAY
4: ShotTimer with RapidShot. Same as 2, with added delay of N fields between each repetition.
5: Manual exposure. Primary counter stays in exposure until manual readout or reset to idle.
6: Manual readout. Primary counter switches to readout (VSG pulses becomes active).
7: Force to idle.
Primary counter maximum value.
Secondary counter maximum value.
Mask VD/HD during counter operation.
ShotTimer. Number of fields to delay before the next primary count (exposure) starts. If using ShotTimer
with RapidShot, delay value is used between each repeat.
When using ShotTimer with RapidShot, use primary delay value only before first count (exposure).
ShotTimer. Number of fields to delay before the next secondary count starts. If using ShotTimer with
RapidShot, delay value is used between each repeat.
When using ShotTimer with RapidShot, use secondary delay value only before first count.
This mode keeps the SUBCK and VSG pulses masked indefinitely.
register).
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The primary counter regulates the expose and read actions by
regulating the SUBCK and VSG signals. If the RapidShot
feature is used with the primary counter, the SUBCK and VSG
masking automatically repeats as necessary for multiple expose/
read cycles. The secondary counter has no effect on the SUBCK
or VSG signal. Both counters can be used to regulate the general-
purpose signals described in the General-Purpose Outputs
(GPOs) section.
ShotDelay with RapidShot
Manual exposure
Manual readout
Force to idle