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Flare 12M CXP User's Manual
3.3 Exposure Mode
The exposure mode of the camera is controlled using the
Exposure Mode
register, address
0x40000014, and there are four options:
➢
Free-run programmable exposure (register value = 0x00000000)
➢
Edge-triggered programmable exposure (register value = 0x00000001)
➢
Edge-triggered level-controlled exposure (register value = 0x00000002)
➢
Edge-triggered double exposure (register value = 0x00000003)
3.3.1 Free-run programmable exposure
In free-run exposure mode an internal timer is used to control the exposure time of a frame.
The primary exposure time is set in microseconds using the
Exposure 1
register, address
0x40000020. The range of the allowable exposure time will change when the frame period
changes (
Frame Period
register, also in microseconds). The timing for this mode, with High
Dynamic Range exposure modes disabled, is shown in Figure 8.
In Figure 8 the example timing is shown with the exposure time less than the readout time.
The fully pipelined architecture of the sensor allows for the next integration period to start
while the previous frame is being read out. There is a Frame Overhead Time (FOT) period
after exposure ends and before the readout of the frame begins. The next exposure cannot
start in the FOT period. The FOT varies with output formats and the image horizontal
resolution, see Table 10.
3.3.2 Edge-triggered programmable exposure
In edge-triggered programmable exposure mode an internal timer is used to control the
exposure of a frame, however, exposure does not start until the active edge of the input
trigger is seen. The primary exposure time is set using the
Exposure 1
register, and the time
IO Industries Inc.
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Revision 2.0
Figure 8. Free-run exposure timing
Exposure Time, Frame N FOT
Readout Time, Frame N
Exposure Time, Frame N+1
FOT
Exposure Time, Frame N+2
Readout Time, Frame N+1
Frame Period
