Silicon Imaging , Inc. 2004 Page 26 of 39 Company Confidential
Frame Snapshot Mode with Global Reset - “f” mode (with Reg21 = x0003)
0x21
Global Reset or ERS
Readout Mode
0x0000 (ERS)
or
0x0003 (GR)
Set to x0003 for Global Reset Snaphsot mode - Release all pixels from
reset simultaneously (use with flash & mechanical shutter. x0000: for ERS.
Default Mode is conitunous ERS
Note: Global reset requires model SI3300–T with external trigger cable.
A further enhancement to the snapshot capability is a global reset mode that enables all pixels to start exposure to
the scene simultaneously. Global reset mode is selected by Reg0x21 to x0003 (x0000 is Rolling Shutter).
Global reset mode has to operate with a mechanical shutter to terminate the exposure time or with a strobe with
minimum ambient light. Using the global reset feature changes the behavior of the row reset controls. Instead of
pulsing, the resets are held on. As the shutter pointer moves through the rows the resets are turned on one by one.
When all of the rows have been reset, the exposure is started by releasing them all together. Exposure is
terminated when an external mechanical shutter cuts off the light. Row read out is performed after the exposure is
terminated. The strobe can be used to control flash and/or a mechanical shutter to end the exposure of the array
prior to readout.
To enter Snaphshot mode with global Reset:
ly210003 <cr>
Global Reset Mode
f <cr>
Frame Snapshot Mode
The snapshot is initiated with the CC-1 Trigger, TTL-Trigger (-T option) signal or “f’ frame request command, as in
ERS snapshot mode. The array is reset row by row before the sensor waits for the trigger. All of the rows are held in
reset until a rising edge is detected on the TRIGGER input, whereupon they are all released at once. At this point
every row in the array starts to integrate at the same time. Integration is terminated and the readout started when the
internal shutter counter is equal to the shutter width register ([Reg0x08, Reg0x09]). The first active row is read out
after the preamble (5 rows), the calibration rows (18 rows) and the dark rows (24 rows), allowing 47 row times for the
mechanical shutter to be closed. (Default values).
To return to Continuous ERS, set Reg21 to ERS Readout (x0000)
and a “c’
ly210000 <cr>
Rolling Shutter Mode
c <cr>
Continuous Readout